KR20150097478A - Zinc oxide-based transparent conductive film - Google Patents

Abstract

A zinc oxide based transparent conductive film comprising a zinc atom, an oxygen atom, and M defined below, wherein the total number of atoms constituting the film is selected from the group consisting of zinc atom number, oxygen atom number, titanium atom number, gallium The total number of atoms and the number of aluminum atoms is 99% or more, and the number of titanium atoms, the number of gallium atoms, and the number of gallium atoms, The ratio of the total number of atoms of aluminum atoms ((number of titanium atoms + number of gallium atoms + number of aluminum atoms) / (number of zinc atoms + number of titanium atoms + number of gallium atoms + number of aluminum atoms) 100) or less, and titanium atoms, gallium atoms, and the number of titanium atoms of at least 50% with respect to the total atom number of aluminum atoms contained in the film, the electron carrier concentration was 3.60 × 10 ²⁰ ㎝ ^-3 or less, mobility is 43.0 ㎠ / Vs or more And a specific resistance of 5.00 x 10 < ^-4 > OMEGA .cm or less.
M: a titanium atom, a titanium atom and a gallium atom, a titanium atom and an aluminum atom, or a titanium atom and a gallium atom and an aluminum atom

Description

Zinc oxide-based transparent conductive film [0002]

The present invention relates to a zinc oxide based transparent conductive film which has a high transmittance in an infrared region and is useful for applications such as solar cells.

The transparent conductive film is a film having visible light transmittance and electric conductivity, and is used in a wide range of fields such as a solar cell, a liquid crystal display element, and an electrode of a light receiving element. As the transparent conductive film, an ITO film in which tin oxide is added to indium oxide, which is referred to as In ₂ O ₃ system, is formed by a sputtering method, an ion plating method, a pulsed laser deposition (PLD) method, an electron beam (EB) Are manufactured and used by a film forming method. However, indium used as a raw material is rare metal, and there is a problem in terms of resource amount, price, etc., and therefore, a film to replace the ITO film is required.

As a most promising alternative material for such an ITO film, a zinc oxide-based film such as AZO in which aluminum is added to zinc oxide, which is referred to as ZnO-based, and GZO in which zinc oxide is added to gallium oxide. These transparent conductive materials such as In ₂ O ₃ -based, ZnO-based, and the like are n-type semiconductors, and carrier electrons exist, and their movement contributes to electric conduction. The carrier electrons in such an oxide transparent conductive film reflect or absorb infrared rays.

Therefore, these films are oxide-transparent conductive films having a high carrier electron concentration, and are excellent in plasma absorption due to the carrier electron concentration and reflection and absorption characteristics at the wavelengths of the near infrared region. Therefore, these films are also used as a transparent heat generating element for anti-fogging such as a heat ray reflecting film used for automobile window glass, a window glass of a building, various antistatic films, and a refrigeration showcase.

Recently, an oxide transparent conductive film has been used in solar cells, photodetecting devices, and the like. However, in these applications, not only the permeability of the visible region but also the permeability of the near-infrared region are important, so that the zinc oxide-based film is not the best material for these uses.

The greatest challenge of solar cells is the conversion efficiency, and it is important how much solar light can be used in the near infrared region, which is not fully utilized to improve the conversion efficiency.

However, if a large number of carrier electrons exist in the film, the film easily reflects and absorbs infrared rays (Non-Patent Documents 1 and 2). That is, when the carrier electron concentration is high, the transmittance of the near infrared rays decreases. In order not to lower the transmittance of near infrared rays, it is required to set the carrier electron concentration to 4.0 x 10 ²⁰ cm ^-3 or less, preferably 3.8 x 10 ²⁰ cm ^-3 or less.

Further, the specific resistivity rho of the material depends on the product of the carrier electron concentration n and the mobility m of the carrier electrons (1 / rho = enu, e being a small charge amount). If the concentration of carrier electrons is lowered in order to increase the transmittance of near infrared rays, it is necessary to increase the mobility μ in order to reduce the resistivity p.

The mobility of an n-type semiconductor such as a zinc oxide-based semiconductor is considered to be mainly dominated by ionization impurity scattering, intergranular scattering, neutral impurity scattering, and the like (impurities contained in the ion state are ionized impurities, The impurities contained in the neutral state are referred to as neutral impurities) (Non-Patent Documents 3 and 4).

A film having a low carrier electron concentration, that is, a film having a high transmittance of near infrared rays can be produced by a method of forming a film by increasing the amount of oxygen introduced at the time of sputtering even when using a zinc oxide-based material. However, in this method, the neutral impurities due to oxygen are increased and the mobility is remarkably lowered. As a result, not only the carrier electron concentration but also the mobility decreases, so that the specific resistance increases.

On the other hand, as another method, there is known a method of decreasing the carrier electron concentration by decreasing the amount of the dopant (aluminum or gallium) added to the aluminum-doped zinc oxide (AZO) and the gallium-doped zinc oxide (GZO). In this method, low carrier concentration and high mobility were expected to be realized while reducing the resistance by reducing the ionization impurity scattering and increasing the mobility (Non-Patent Documents 5 to 9).

If mobility is dominated mainly by ionization impurity scattering, mobility will increase with decreasing carrier electron concentration because mobility is proportional to -2/3 power of carrier electron concentration. However, in a film doped with gallium or aluminum which is considered to have the lowest resistance, the mobility decreases with the decrease of the carrier electron concentration, and as a result, the resistivity increases (Non-Patent Documents 5 to 9). This is presumably because only ionized impurity scattering is not a dominant factor and neutral impurity scattering or interstitial scattering affects the resistivity.

Non-Patent Document 10 describes a zinc oxide-based transparent conductive film doped with boron, which has a carrier electron concentration of 2 x 10 ²⁰ cm ^-3 , a mobility of 60 cm 2 / Vs and a specific resistance of 4 x 10 ^-4 Ω · cm. Non-Patent Documents 11 and 12 disclose a zinc oxide-based transparent conductive film doped with aluminum. These films have a mobility of 40 to 67 cm 2 / Vs and a specific resistance of 3.8 × 10 ^-4 Ω · cm or less.

However, the film of the non-patent document 10 doped with boron is inferior in chemical durability and can not withstand practical use. The membranes of non-patent documents 11 and 12 doped with aluminum have a low doping amount of aluminum and are inferior in chemical durability. Further, the film of the non-patent document 12 has the silicon barrier layer formed, and the manufacturing process becomes complicated.

For example, Patent Document 1 describes a zinc oxide based transparent conductive film having improved chemical durability and near-infrared region transmittance. However, although the transparent conductive film of Patent Document 1 is improved in chemical durability and transparency in the near infrared region, it can be calculated from the sheet resistance and film thickness to be 7.4 × 10 ^-4 to 8.0 × 10 ^-4 Ω · cm. This is an excessively high value for use as a transparent conductive film.

As described above, there is no transparent oxide electroconductive transparent conductive film having excellent permeability, low resistance, and excellent chemical durability (heat and humidity resistance and heat resistance) even in the near infrared region (800 to 2500 nm).

Japanese Laid-Open Patent Publication No. 2012-92003

 Technology of Transparent Conductive Film, Compiled by Japan Academic Promotion Association, Oompa, p.56 ~ 60  Ultrafine Solar Cells, Frontiers of Related Materials, p.68 ~ 71  Frontiers of ultra-efficient solar cells and related materials (SHM Co., Ltd.), p.65 ~ 68  The latest transparent conductive film charging house (characteristics of material and substitute prospect / know-how by recycling, process, demand characteristics by application) (Information equipment) p.87  TOSOH Research & Technology Review Vol.54 (2010)  Monthly Display September 1999 issue 14 page  Applied Physics Volume 61, Issue 12 (1992)  Japanese Journal of Applied Physics Vol.47, No.7, 2008, pp.5656-5658  Journal of Non-Crystalline Solids 218 (1997), pp. 233-328  Jpn. J. Appl. Phys. Vol. 34 (1995) Part 1, No. 7A, pp. 3623-3627  J. Appl. Phys., Vol. 95, No. 4, 15 February 2004, pp. 1911-1917  JOURNAL OF APPLIED PHYSICS 107, 013708 (2010), 013708-1 to 013708-8

The object of the present invention is to provide a transparent oxide conductive film of zinc oxide which is excellent in permeability even in the near infrared region (800 to 2500 nm), low in resistance, and also excellent in chemical durability (heat and humidity resistance and heat resistance).

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and as a result, found a solution comprising the following constitution, and have completed the present invention.

(1) A zinc oxide based transparent conductive film comprising zinc atoms, oxygen atoms, and M defined below, wherein the number of zinc atoms, the number of oxygen atoms, and the number of titanium atoms , The total number of gallium atoms and aluminum atoms is 99% or more, and the total number of atoms of the zinc atoms, the titanium atoms, the gallium atoms and the aluminum atoms contained in the film is the number of titanium atoms, gallium The ratio of (the number of titanium atoms + the number of gallium atoms + the number of aluminum atoms) / (the number of zinc atoms + the number of titanium atoms + the number of gallium atoms + the number of aluminum atoms) 100) of the total number of atoms of the atomic number and the number of aluminum atoms was 1.3% Or more and 2.0% or less, and the number of titanium atoms is at least 50% and the carrier electron concentration is 3.60 x 10 ²⁰ cm ^-3 or less based on the total number of atoms of titanium atoms, gallium atoms, and aluminum atoms contained in the film, Mobility of 43.0 ㎠ / Vs Shape, and the resistivity of 5.00 × 10 ^-4 Ω · ㎝ than zinc oxide based transparent conductive film.

M: a titanium atom, a titanium atom and a gallium atom, a titanium atom and an aluminum atom, or a titanium atom and a gallium atom and an aluminum atom

(2) The ratio of the total number of atoms of the titanium atom number, the gallium atom number, and the aluminum atom number (((number of titanium atoms + number of gallium atoms The number of zinc atoms, the number of zinc atoms, the number of titanium atoms, the number of gallium atoms, and the number of aluminum atoms) × 100) is 1.3% or more and 1.9% or less.

(3) The transparent conductive film made of zinc oxide based on (1) or (2), wherein the sheet resistance at a film thickness of 500 nm is 10 Ω / □ or less.

(4) A sintered body comprising a zinc atom, an oxygen atom, and M defined below, wherein the number of zinc atoms, the number of oxygen atoms, the number of titanium atoms, and the number of gallium atoms And the total number of aluminum atoms is 99% or more, and the number of titanium atoms, the number of gallium atoms, and the number of gallium atoms, the number of gallium atoms, and the number of gallium atoms relative to the total number of atoms of zinc atoms, (Number of titanium atoms + number of gallium atoms + number of aluminum atoms) / (number of zinc atoms + number of titanium atoms + number of gallium atoms + number of aluminum atoms) x 100) of 1.3 to 2.0% , The number of titanium atoms is at least 50% and the relative density is at least 96.5% with respect to the total number of atoms of the titanium atoms, the gallium atoms and the aluminum atoms contained in the sintered body, and the L * a * b * b * is 0.00 or more, L * 46.00 or less sintered body.

M: a titanium atom, a titanium atom and a gallium atom, a titanium atom and an aluminum atom, or a titanium atom and a gallium atom and an aluminum atom

(5) The ratio of the total number of titanium atoms, the number of gallium atoms and the number of aluminum atoms to the total number of atoms of zinc atoms, titanium atoms, gallium atoms, and aluminum atoms ((number of titanium atoms + number of gallium atoms + Number of aluminum atoms) / (number of zinc atoms + number of titanium atoms + number of gallium atoms + number of aluminum atoms) x 100) is 1.3% or more and 1.9% or less.

(6) A method for producing a sintered body containing a zinc atom, an oxygen atom and M defined below, comprising the steps of putting a raw material containing a zinc source and an M source into a mold, As the process, the M source is represented by (i) to (iv) below,

(i) at least one titanium source selected from the group consisting of low valence titanium oxide, titanium black, titanium carbide and titanium nitride,

(ii) a mixture of the titanium source and at least one gallium source selected from the group consisting of gallium oxide and gallium nitride,

(iii) a mixture of the titanium source, at least one aluminum source selected from the group consisting of aluminum oxide, aluminum carbide and aluminum nitride,

(iv) mixing the titanium source, the gallium source, and the aluminum source,

Press-sintering a raw material in a mold at a temperature of 900 to 1200 占 폚 and a pressure of 20 to 50 MPa in a vacuum or in an inert atmosphere for 2 to 5 hours, wherein the total number of atoms contained in the sintered body The total number of zinc atoms, the number of oxygen atoms, the number of titanium atoms, the number of gallium atoms and the number of aluminum atoms is 99% or more, and the number of zinc atoms, the number of titanium atoms, the number of gallium atoms (Number of titanium atoms + number of gallium atoms + number of aluminum atoms) / (number of zinc atoms + number of titanium atoms) of the total number of titanium atoms, the number of gallium atoms, and the number of aluminum atoms + The number of gallium atoms + the number of aluminum atoms) x 100) is not less than 1.3% and not more than 2.0%, the number of titanium atoms is less than the total number of titanium atoms, gallium atoms and aluminum atoms contained in the sintered body A method for producing a sintered body of 50%.

M: a titanium atom, a titanium atom and a gallium atom, a titanium atom and an aluminum atom, or a titanium atom and a gallium atom and an aluminum atom

(7) A process for producing a sintered body containing a zinc atom, an oxygen atom, and M as defined below, comprising the step of putting a raw material containing a zinc source and an M source into a die, To (iv)

(i) at least one titanium source selected from the group consisting of low valence titanium oxide, titanium black, titanium carbide and titanium nitride,

(ii) a mixture of the titanium source and at least one gallium source selected from the group consisting of gallium oxide and gallium nitride,

(iii) a mixture of the titanium source, at least one aluminum source selected from the group consisting of aluminum oxide, aluminum carbide and aluminum nitride,

(iv) mixing the titanium source, the gallium source, and the aluminum source,

A step of sintering a raw material in a die at a temperature of 900 to 1200 占 폚 and a pressure of 20 to 50 MPa for 5 to 30 minutes by discharge plasma sintering, , The total number of oxygen atoms, the number of titanium atoms, the number of gallium atoms and the number of aluminum atoms is 99% or more, and the total atom number of zinc atoms, the number of titanium atoms, the number of gallium atoms and the number of aluminum atoms (The number of titanium atoms + the number of gallium atoms + the number of aluminum atoms) / (the number of zinc atoms + the number of titanium atoms + the number of gallium atoms + the number of gallium atoms + the number of gallium atoms) The number of titanium atoms is at least 50% with respect to the total number of atoms of titanium atoms, gallium atoms and aluminum atoms contained in the sintered body, method.

M: a titanium atom, a titanium atom and a gallium atom, a titanium atom and an aluminum atom, or a titanium atom and a gallium atom and an aluminum atom

(8) A method for producing a sintered body including a zinc atom, an oxygen atom and M defined below, wherein a raw material containing a zinc source and an M source is contained in a metal capsule in an amount of 50% Wherein the M source is any of the following (i) to (iv)

(i) at least one titanium source selected from the group consisting of low valence titanium oxide, titanium black, titanium carbide and titanium nitride,

(ii) a mixture of the titanium source and at least one gallium source selected from the group consisting of gallium oxide and gallium nitride,

(iii) a mixture of the titanium source, at least one aluminum source selected from the group consisting of aluminum oxide, aluminum carbide and aluminum nitride,

(iv) mixing the titanium source, the gallium source, and the aluminum source,

And a step of subjecting the capsule raw material to hot isostatic pressing at 900 to 1400 캜 for 1 to 4 hours while pressurizing the charged raw material in an inert gas atmosphere to 50 MPa or more,

Wherein the total of the number of zinc atoms, the number of oxygen atoms, the number of titanium atoms, the number of gallium atoms and the number of aluminum atoms is 99% or more, the number of zinc atoms contained in the sintered body, The ratio ((number of titanium atoms + number of gallium atoms + number of aluminum atoms) / (number of titanium atoms) of the total number of titanium atoms, the number of gallium atoms and the number of aluminum atoms to the total number of atoms of titanium atoms, The number of zinc atoms + the number of titanium atoms + the number of gallium atoms + the number of aluminum atoms) x 100) is not less than 1.3% and not more than 2.0%, and the total number of atoms of titanium atom, gallium atom and aluminum atom contained in the sintered body Wherein the number of titanium atoms is at least 50%.

M: a titanium atom, a titanium atom and a gallium atom, a titanium atom and an aluminum atom, or a titanium atom and a gallium atom and an aluminum atom

(9) the ratio of the total number of atoms of the titanium atom number, the number of gallium atoms and the number of the aluminum atoms (((number of titanium atoms + number of gallium atoms) to the total number of atoms of the zinc atoms, (6) to (8), wherein the number of atoms is the number of atoms + the number of aluminum atoms / (the number of zinc atoms + the number of titanium atoms + the number of gallium atoms + the number of aluminum atoms) × 100) .

(10) A process for producing a transparent electroconductive film of a zinc oxide-based transparent conductive film, which comprises the step of providing a sintered body according to (4) or (5) above to a sputtering method, an ion plating method or an electron beam vapor deposition method, Way.

(11) A transparent conductive substrate comprising the zinc oxide based transparent conductive film according to any one of (1) to (3) on a transparent substrate.

(12) A light-emitting device comprising a light absorbing layer made of a p-type semiconductor, an intermediate layer made of an n-type semiconductor, a window layer made of an n-type semiconductor, Wherein a transparent conductive film layer made of a zinc oxide based transparent conductive film described in any one of claims 1 to 3 is laminated in this order.

(13) A method for manufacturing a semiconductor device, comprising the steps of: forming on a transparent substrate a transparent electrode layer made of a zinc oxide based transparent conductive film according to any one of (1) to (3), a window layer made of an n-type semiconductor, A light absorption layer, and a metal electrode are laminated in this order.

(14) The compound solar cell according to (12) or (13), wherein the light absorbing layer is made of at least one selected from CuInSe ₂ , CuInS ₂ , CuGaSe ₂ , CuGaS ₂ , solid solutions thereof, and CdTe.

(15) The compound solar cell according to (12) or (13), wherein the light absorption layer is made of at least one selected from CuZnSe ₂ , CuZnS ₂ , CuSnSe ₂ , CuSnS ₂ and solid solutions thereof.

(16) A silicon-based solar cell in which a first electrode layer, a light absorbing layer and a second electrode layer are laminated in this order and a photovoltaic power is generated by light incident from the second electrode layer side, wherein the first electrode layer and the second Wherein at least the second electrode layer of the electrode layer is made of a zinc oxide-based transparent conductive film described in any one of (1) to (3).

(17) The silicon-based solar cell according to (16), wherein the light-absorbing layer is composed of at least one selected from the group consisting of amorphous silicon type, polycrystalline silicon type, and microcrystalline silicon type.

The zinc oxide based transparent conductive film related to the present invention is excellent in permeability, low resistance, and chemical durability (resistance to humid heat and heat) even in the near infrared region (800 to 2500 nm). Therefore, when the transparent conductive oxide based transparent conductive film according to the present invention is used for a solar cell, for example, it is possible to use solar energy in the near infrared region, which has not been conventionally available, with high efficiency, Solar cells can be obtained.

1 is a cross-sectional view showing a compound thin film solar cell fabricated in Example 14. Fig.

The zinc oxide based transparent conductive film of the present invention has a carrier electron concentration of 3.60 × 10 ²⁰ cm ^-3 or less, a mobility of 43.0 cm 2 / Vs or more, and a specific resistance of 5.00 × 10 ^-4 Ω · cm or less.

As described above, in order not to lower the transmission of near infrared rays, it is necessary to set the carrier electron concentration to 4.0 x 10 ²⁰ cm ^-3 or less. The conventional ITO film, AZO film, GZO film and the like have a low resistance. Since the carrier electron concentration is usually 6.0 x 10 ²⁰ cm ^-3 or more, it absorbs or reflects near infrared rays having a wavelength of 1000 nm or more, will be.

Therefore, in order to improve the transmittance in the near infrared region, the carrier electron concentration in the zinc oxide based transparent conductive film of the present invention is 3.60 x 10 ²⁰ cm ^-3 or less. As described above, when the carrier electron concentration is low, it becomes difficult to absorb or reflect infrared rays, and the transmittance is improved. The zinc oxide based transparent conductive film of the present invention preferably has a carrier electron concentration of 3.30 × 10 ²⁰ cm ^-3 or less, more preferably 3.10 × 10 ²⁰ cm ^-3 or less.

The resistivity of the material depends on the product of the carrier electron concentration n and the mobility μ of the carrier electrons as described above (1 / p = enμ, e is the charge amount). Therefore, if the concentration of carrier electrons is lowered in order to improve the transmittance in the near-infrared region, unless the mobility is increased, the resistivity increases and the film can not be used as a transparent conductive film.

Thus, the zinc oxide-based transparent conductive film of the present invention has a carrier electron concentration of 3.60 x 10 ²⁰ cm ^-3 or less, but the mobility is as large as 43.0 cm 2 / Vs or more. In addition, since the conventional ITO film has a mobility of about 20 to 30 cm 2 / Vs, it can be seen that the zinc oxide based transparent conductive film of the present invention has a large mobility.

As described above, since the zinc oxide based transparent conductive film of the present invention has a high mobility of 43.0 cm 2 / Vs or more even when the carrier electron concentration is as low as 3.60 × 10 ²⁰ cm ^-3 or less, the specific resistance is 5.00 × 10 ^-4 Ω · cm And low resistance.

The zinc oxide based transparent conductive film of the present invention is a zinc oxide based transparent conductive film containing zinc atoms, oxygen atoms and M as defined below, wherein the number of zinc atoms and oxygen The total number of atomic numbers, the number of titanium atoms, the number of gallium atoms, and the number of aluminum atoms is 99% or more, and the total number of atoms of the zinc atoms, the titanium atoms, the gallium atoms, (The number of titanium atoms + the number of gallium atoms + the number of aluminum atoms) / (the number of zinc atoms + the number of titanium atoms + the number of gallium atoms + the number of aluminum atoms) of the total number of atoms of titanium atoms, ) × 100) is not less than 1.3% and not more than 2.0%, the number of titanium atoms is at least 50% of the total number of atoms of titanium atoms, gallium atoms and aluminum atoms, and the carrier electron concentration is 3.60 × 10 ^{20 -3} or less, and the mobility is 43.0 ㎠ / Vs or more, and the specific resistance is not more than 5.00 × 10 ^-4 Ω · ㎝ zinc-based transparent conductive oxide film.

M: a titanium atom, a titanium atom and a gallium atom, a titanium atom and an aluminum atom, or a titanium atom and a gallium atom and an aluminum atom

The total number of atoms of the titanium atom, the gallium atom and the aluminum atom with respect to the total number of atoms of the zinc atom number, the titanium atom number, the gallium atom number and the aluminum atom number contained in the zinc oxide based transparent conductive film of the present invention The ratio is preferably 1.3% or more and 1.9% or less, more preferably 1.4% or more and 1.9% or less.

The number of titanium atoms relative to the total number of atoms of the titanium atom number, the gallium atom number, and the aluminum atom number contained in the zinc oxide-based transparent conductive film of the present invention is preferably 55% or more.

A chemical durability (heat and humidity resistance and heat resistance) is also required for the transparent oxide conductive film.

Even in the case of a transparent oxide conductive film having the same specific resistance, the film having a low carrier electron concentration and high mobility has a higher permeability in the near infrared region because the plasma absorption is lower than that of a film having a high carrier electron density and low mobility. Carrier electrons fluctuate in the amount of oxygen deficiency due to changes in the temperature and humidity of the outside world, trapped in adsorbed oxygen, adsorbed water, and the like, so carrier electron concentrations tend to fluctuate.

On the other hand, the mobility is easy to move the electrons and is not well affected by the change of the outside world. Therefore, the resistivity of the transparent conductive film depends on the mobility rather than depending on the carrier electrons, and the resistivity is not influenced by the change of the external environment. That is, even a transparent conductive film having the same composition and the same specific resistance, the transparent conductive film having a low carrier electron density and high mobility has a chemical durability better than that of the transparent conductive film having a high carrier electron density and low mobility. Therefore, the zinc oxide-based transparent conductive film of the present invention has chemical durability (wet heat resistance and heat resistance) superior to the chemical durability of the zinc oxide-based transparent conductive film made of conventional AZO or GZO even when the amount of titanium doped is small.

In the single doping of aluminum or gallium, even if the doping amount is reduced from the optimum amount of doping (the doping amount is 2.0% (atomic ratio) in the case of aluminum and the doping amount is 4.4% (atomic ratio) in the case of gallium) Since it is dominated by neutral impurity scattering and grain boundary scattering, the mobility never increases.

However, in the case of titanium doping, even if the total doping amount is 2.0% or less (atomic ratio), the mobility is not influenced by neutral impurity scattering and grain boundary scattering, and is controlled only by ionization impurity scattering. In the case of titanium doping, the doping amount shows a very high mobility specifically around 1.5%. It has been found that the mobility begins to deteriorate under the influence of neutral impurity scattering and intergranular scattering only by making the doping amount smaller. Further, when the total amount of doping is in the range of 1.3% or more and 2.0% or less, it was found that the same behavior is exhibited also in the case of titanium and aluminum, titanium and gallium, or cobbles of titanium, aluminum and gallium. In the case of the cord, the number of atoms of titanium is at least 50% with respect to the total number of atoms of titanium, gallium and aluminum.

In the case of AZO not containing titanium, when the doping amount is 2.0% or less, neutral impurity scattering and intergranular scattering become dominant factors of mobility, and the mobility decreases continuously as the doping amount is reduced. When the doping amount of aluminum or gallium is 2.0% or less, mobility can be improved by improving the crystallinity by providing the obtained film to a post-treatment (for example, annealing under hydrogen atmosphere). However, since the amount of doping of aluminum or gallium is less than that of aluminum, the chemical durability (wet heat resistance and heat resistance) of the resultant film is very poor, and it can not withstand practical use.

The zinc oxide based transparent conductive film of the present invention is a zinc oxide based transparent conductive film containing zinc atoms, oxygen atoms and M as defined below, wherein the number of zinc atoms and oxygen The total number of atomic numbers, the number of titanium atoms, the number of gallium atoms, and the number of aluminum atoms is 99% or more, and the total number of atoms of the zinc atoms, the titanium atoms, the gallium atoms, (The number of titanium atoms + the number of gallium atoms + the number of aluminum atoms) / (the number of zinc atoms + the number of titanium atoms + the number of gallium atoms + the number of aluminum atoms) of the total number of atoms of titanium atoms, ) X 100) is not less than 1.3% and not more than 2.0%, and the number of titanium atoms is at least 50% with respect to the total number of atoms of titanium atoms, gallium atoms and aluminum atoms contained in the film.

M: a titanium atom, a titanium atom and a gallium atom, a titanium atom and an aluminum atom, or a titanium atom and a gallium atom and an aluminum atom

The zinc oxide-based transparent conductive film of the present invention is excellent in permeability, near-infrared region (800 to 2500 nm), low resistance, and excellent in chemical durability (heat and humidity resistance and heat resistance).

The zinc oxide-based transparent conductive film of the present invention is a transparent conductive film made of a zinc oxide-based transparent conductive film containing at least one element selected from the group consisting of tin atoms, silicon atoms, germanium atoms, zirconium atoms, hafnium atoms, indium atoms, iridium atoms, ruthenium atoms, A niobium atom, a tantalum atom, a scandium atom, a yttrium atom, a lanthanum atom and a boron atom. Since these atoms are contained as trace atoms, the total number of these atoms relative to the total amount of all metal atoms constituting the transparent conductive film is preferably 0.1% or less.

The zinc oxide based transparent conductive film of the present invention is formed by providing the sintered body of the present invention to be described later, for example, by a sputtering method, an ion plating method, a pulsed laser deposition (PLD) method, an electron beam (EB)

The film formation by the sputtering method is carried out as follows. First, a substrate and a target (sputtering target) are arranged in a sputtering apparatus. Subsequently, a thin film is formed on the substrate by heating the substrate at a predetermined temperature in an argon inert gas atmosphere containing oxygen gas, and applying an electric field between the substrate and the target to generate plasma between the target and the substrate.

The film formation by the ion plating method is carried out as follows. First, a substrate and a target (tablet for ion plating) are placed in a copper hearth of an ion plating apparatus. Subsequently, the substrate is heated at a predetermined temperature in an argon inert gas atmosphere containing oxygen gas, and the target is evaporated from the copper hearth using an electron gun. Subsequently, the target vapor is ionized by generating a plasma in the vicinity of the substrate, thereby forming a thin film on the substrate.

The structure and crystallinity of the zinc oxide-based transparent conductive film depend on film forming conditions such as the composition of the target, the heating temperature of the substrate, the oxygen partial pressure in the inert gas atmosphere, and the deposition rate. The above-mentioned method is an example, but the zinc oxide based transparent conductive film of the present invention can be obtained in this way.

(Sintered body)

The sintered body of the present invention is a sintered body containing zinc atoms, oxygen atoms, and M defined below, wherein the number of zinc atoms, the number of oxygen atoms, the number of titanium atoms and the number of titanium atoms , The total number of gallium atoms and aluminum atoms is 99% or more, and the number of titanium atoms, the number of gallium atoms, the number of gallium atoms, the number of gallium atoms (Number of titanium atoms + number of gallium atoms + number of aluminum atoms) / (number of zinc atoms + number of titanium atoms + number of gallium atoms + number of aluminum atoms) 100) of the total number of aluminum atoms And the relative density is 96.5% or more with respect to the total number of titanium atoms, the number of gallium atoms and the total number of aluminum atoms contained in the sintered body, and the ratio of the number of titanium atoms in the L * a * b * B * Is not less than 0.00 and L * is not more than 46.00.

M: a titanium atom, a titanium atom and a gallium atom, a titanium atom and an aluminum atom, or a titanium atom and a gallium atom and an aluminum atom

The ratio of the total number of titanium atoms, the number of gallium atoms and the number of aluminum atoms to the total number of atoms of the zinc atoms, the titanium atoms, the gallium atoms and the aluminum atoms contained in the sintered body of the present invention is 1.3% Or more and 1.9% or less, and more preferably 1.4% or more and 1.9% or less.

The number of titanium atoms to the total number of atoms of the titanium atom, the gallium atom and the aluminum atom contained in the sintered body of the present invention is preferably 55% or more.

The relative density of the sintered body of the present invention is 96.5% or more, preferably 97% or more, and more preferably 98% or more from the viewpoints of mechanical strength and suppression of arcing (abnormal discharge) of the sintered body. The upper limit of the relative density is 100%. The relative density is a value obtained by the following method.

The relative density in this specification is the ratio of the density of the sintered body actually obtained to the theoretical density. The relative density is expressed by the following equation.

Relative density = 100 x [(density of sintered body) / (theoretical density)]

The theoretical density is obtained by the following method. First, the density of each component used in the production of the sintered body is multiplied by the ratio of the weight of the components when the total weight of the components used for manufacturing the sintered body is 1. This is calculated for all the used components, and their sum is made the theoretical density.

For example, when a sintered body is produced using zinc oxide as a zinc source and titanium oxide as an M source, the theoretical density for obtaining the relative density of the sintered body is obtained by the following equation. The density of the sintered body was measured by the method described in the examples.

Theoretical density = (density of zinc oxide x mixing weight ratio + density of titanium oxide x mixing weight ratio)

If the relative density is low, there is a fear that the feature of high film forming speed is hindered.

In order to obtain a sintered body having a high relative density, the sintering temperature at the time of producing the sintered body by the method described later is important. In any of these methods, it is predicted that the relative density is increased when the sintering temperature is raised. However, if the sintering temperature is excessively high in practice, the zinc source is reduced and becomes metal zinc. Since the melting point of metallic zinc is 470 캜, it volatilizes at the sintering temperature. Since the volatilized portion of the metal zinc becomes porous, the resultant sintered body becomes low in density on the contrary. The sintering temperature which can suppress the reduction of zinc oxide and can be densified is preferably 1000 ° C to 1200 ° C.

In order to obtain a sintered body having a high relative density by using powder as a raw material for producing a sintered body, it is preferable to use a powder having an average primary particle size of 0.2 to 5 탆. Generally, the smaller the average primary particle size is, the larger the specific surface area becomes and the sintering becomes easy, but the secondary aggregation becomes easier.

The sintered body of the present invention has b * of 0.00 or more and L * of 46.00 or less in the L * a * b * colorimetric system measured in the CIE 1976 space. The L * a * b * color space (JIS Z8729) is a color space based on the xyz color system, the L * value indicates lightness, a * and b * are chromaticity coordinates, and hue and saturation are shown together. The L * value represents only the brightness (brightness) regardless of the color, and is a value from L * = 0 (black) to L * = 100 (white). a * denotes the axis from red to green, + a * denotes the red direction, and -a * denotes the green direction. b * denotes the axis from yellow to blue, + b * denotes the yellow direction, and -b * denotes the blue direction.

L * is 46.00 or less, more preferably 45.00 or less, and further preferably 43.00 or less. b * is 0.00 or more, and more preferably 1.00 or more.

A colorimeter is used for these measurements. Specifically, it is measured by the following method. First, a sample (L *, a *, b *) in a L * a * b * colorimetric system is used as a standard sample. Measure and verify that it matches a known value. After confirming that the measured value agrees with the known value, the sample is measured. The surface roughness of the surface to be measured is 0.5 占 퐉 or less. If necessary, the surface of the sample is polished.

it is not certain why the transparent conductive film of zinc oxide based on the zinc oxide-based material exhibiting the effect of the present invention can be obtained by using the sintered body of the present invention in which each of b * and L * satisfies the above requirements. By adjusting the kind of the titanium source, the method and condition for producing the sintered body, and the ratio of the titanium atom in the sintered body, a sintered body in which each of b * and L * satisfies the requirements of the present invention is obtained. As the relative density increases, the L * value tends to decrease. In the case of the same titanium source, the L * value tends to decrease as the titanium content increases.

In order to produce the sintered body containing zinc atoms, oxygen atoms and M according to the present invention, a raw material including a zinc source and an M source is used. The zinc source is a substance that provides a zinc atom contained in the sintered body, and the M source is a substance that provides a source of M contained in the sintered body. The M circle is any of the following (i) to (iv).

(i) at least one titanium source selected from the group consisting of low valence titanium oxide, titanium black, titanium carbide and titanium nitride,

(ii) a mixture of the titanium source and at least one gallium source selected from the group consisting of gallium oxide and gallium nitride,

(iii) a mixture of the titanium source, at least one aluminum source selected from the group consisting of aluminum oxide, aluminum carbide and aluminum nitride,

(iv) a mixture of the titanium source, the gallium source, and the aluminum source.

The raw material is usually a granulated product obtained by granulating powder or powder, or a molded product obtained by molding powder or granulated product. The pre-fired powder can also be used as the raw material. The preliminary firing is a method of firing the powder at 900 to 1300 캜 in a non-oxidizing atmosphere.

The granules are produced, for example, in the following manner. The raw material of the powder and the aqueous solvent are mixed, and the obtained slurry is sufficiently mixed by wet mixing. The mixture is subjected to solid-liquid separation, and the obtained solid is dried and assembled. The wet mixing may be performed by, for example, a wet ball mill or a vibrating mill using a hard ZrO ₂ ball or the like, and a mixing time when using a wet ball mill or a vibrating mill is preferably about 12 to 78 hours. The raw material of the powder may be dry-mixed directly, but wet mixing is more preferable. For solid-liquid separation, drying and assembly, known methods may be employed respectively.

Since the granulated material has high fluidity at the time of molding, the productivity of the molded product is excellent. The method of assembly is not particularly limited, but may include spray drying and assembly. The average particle diameter of the granules is usually several mu m to 1000 mu m.

Examples of the method for producing a molded article from the granulated product include a press forming method, a cold isostatic pressing (CIP) forming method, an injection molding method, an injection molding method and the like. When the assembly is put in a mold frame and press-formed, it can be molded at 500 kg / cm 2 to 3.0 ton / cm 2. In the case of using a cold forming machine such as a cold press or a cold isostatic press, it is possible to apply a pressure of 1 ton / cm 2 or more.

When a molded article is produced from the granulated product, it is preferable to mix the powder with the binder at the time of manufacturing the granulated product. Examples of the binder include polyvinyl alcohol, acrylic polymer, methyl cellulose, vinyl acetate, waxes, oleic acid, and the like. In the case of using a binder, it is preferable to degrease the molded body in order to prevent breakage such as cracking during heating.

Examples of the zinc source include zinc oxide and zinc hydroxide. As zinc oxide, ZnO having a normal Wurtzite structure is used, and ZnO in which oxygen deficiency is generated by previously firing the ZnO in an inert atmosphere or a reducing atmosphere may be used. The zinc hydroxide may be amorphous or may have a crystal structure. When a zinc oxide powder or a zinc hydroxide powder is used as a raw material, the fine powder has excellent homogeneity and sinterability in a mixed state. Therefore, the average primary particle size of the powder is preferably 5 占 퐉 or less, and more preferably 1.5 占 퐉 or less.

The titanium source is selected from the group consisting of low valence titanium oxide, titanium black, titanium carbide and titanium nitride. You may choose two or more of them in the group. Generally speaking, titanium oxide is TiO ₂ (IV) in which the valence of titanium is tetravalent. The low valent titanium oxide is titanium oxide having a valence lower than that of tetravalent. Examples of the low-valent titanium oxide include TiO (II) and Ti ₂ O ₃ (III). The titanium source is preferably TiO (II), titanium carbide, or a mixture thereof.

When a powder is used as the titanium source, the average primary particle size of the titanium-causing powder is not particularly limited, but is preferably 2 占 퐉 or less, and more preferably 1 占 퐉 or less.

The gallium source is at least one selected from the group consisting of gallium oxide and gallium nitride. The aluminum source is at least one selected from the group consisting of aluminum oxide, aluminum carbide and aluminum nitride.

When a powder is used as a gallium source or an aluminum source, the average primary particle size of the powder is not particularly limited, but is preferably 2 m or less, more preferably 1 m or less.

The mixing ratio of the zinc source and the M source may be appropriately set so that the finally obtained sintered body satisfies the following requirements. The requirement is that the total of the number of zinc atoms, the number of oxygen atoms, the number of titanium atoms, the number of gallium atoms and the number of aluminum atoms is 99% or more with respect to the total number of atoms contained in the sintered body, The ratio ((number of titanium atoms + number of gallium atoms + number of gallium atoms + number of aluminum atoms) of the total number of titanium atoms, the number of gallium atoms and the number of aluminum atoms with respect to the total number of atoms of zinc atoms, (Number of zinc atoms + number of titanium atoms + number of gallium atoms + number of aluminum atoms) x 100) is 1.3% or more and 2.0% or less, and the sum of the number of titanium atoms, the number of gallium atoms, and the number of aluminum atoms contained in the sintered body The number of titanium atoms relative to the number of atoms is at least 50%.

The easiness of the volatilization of zinc differs depending on the atmosphere at the time of sintering. For example, in the case of using zinc oxide, only sintering in an air atmosphere or an oxidizing atmosphere causes sintering of the zinc oxide itself. However, when sintering is performed in an inert atmosphere or a reducing atmosphere, zinc oxide is reduced, As it becomes zinc, the loss of zinc increases.

Therefore, the extent to which the amount of the zinc source is increased with respect to the target composition may be set in consideration of the sintering atmosphere and the like. In the case of sintering in an inert atmosphere or a reducing atmosphere, a zinc source in an amount of about 1.05 to 1.2 times as much as the desired atomic ratio is used.

The sintered body of the present invention is produced by the following method (1), (2) or (3).

(1) a step of putting a raw material into a mold, and a step of hot-pressing and sintering the raw material in a mold at a temperature of 900 to 1200 ° C under a vacuum or in an inert atmosphere at a pressure of 20 to 50 MPa for 2 to 5 hours How to.

(2) a step of putting the raw material into the die, and a step of sintering the raw material in the die by discharge plasma at a temperature of 900 to 1200 DEG C and a pressure of 20 to 50 MPa for 5 to 30 minutes.

(3) a step of filling the raw material in a capsule made of metal so that the filling rate of the raw material is 50% or more, and the step of pressing the raw material charged in an inert gas atmosphere at 900 to 1400 캜 for 1 to 4 hours , And performing a capsule hot isostatic pressing and sintering.

(1) will be described. The hot press method (HP method) is a method in which a predetermined amount of a raw material is put into a carbon dice, sandwiched by a carbon punch, pressurized uniaxially in a vacuum or in an inert gas atmosphere such as Ar at 900 to 1200 占 폚, And the whole is heated. The pressure at sintering is 20 to 50 MPa, and the sintering time is 2 to 5 hours. The hot press sintering method can simultaneously perform molding and sintering.

(2) will be described. The discharge plasma sintering method (SPS method) is a method in which a predetermined amount of a raw material is placed in a carbon dice, placed in a carbon punch, placed in a discharge plasma sintering (SPS) apparatus, and subjected to discharge plasma sintering . The sintering temperature is 900 to 1200 ° C, the pressure is 20 to 50 MPa, and the sintering time is 5 to 30 minutes. The SPS method can simultaneously perform molding and sintering.

The SPS device is composed of a sintering machine body having a vertical uniaxial pressing mechanism, a special energizing mechanism with a water cooling section, a water-cooling vacuum chamber, an atmosphere control mechanism, a vacuum exhaust device, a special DC pulse power source, When a die or punch mold filled with a raw material is set on a sintering stage in a chamber and sandwiched by electrodes and subjected to pulse energization while being pressurized, depending on the size of the carbon dies and the carbon punch, The temperature is rapidly raised from room temperature to a predetermined temperature. Therefore, when this device is used, a high-density sintered body can be obtained in a short time.

(3) will be described. The hot isostatic pressing method (HIP method) is a method of applying a high pressure at a high temperature and an isotropic pressure to a raw material, and sintering the raw material using a synergistic effect of high temperature and high pressure. The HIP method includes a capsule method and a capsule-free method. Hereinafter, the capsule HIP method (capsule HIP treatment) which is the method of the present invention will be described.

First, the raw material is filled in a metal capsule so that the filling rate becomes 50% or more. By setting the fill factor of the raw material to 50% or more, it is difficult for the capsules themselves to be damaged by the applied pressure during the capsule HIP process. The filling rate is a ratio of the filling amount of the raw material to the theoretical density of the sintered body obtained after the capsule HIP reaches the theoretical density and is represented by the following formula.

Charging rate (%) = 100 x (charge amount of raw material / theoretical density of sintered body)

The capsule filled with the raw material is provided for vacuum degassing treatment. The vacuum degassing treatment is carried out, for example, by exhausting from an exhaust pipe connected to a capsule and depressurizing the inside of the capsule (vacuum treatment). After the decompression (vacuum treatment), check the helique and check the integrity (no leakage) of the capsule welded part. Decompression (vacuum treatment) is carried out while heating the capsule filled with the raw material until the pressure in the capsule is usually 1.33 x ^10-2 Pa or less. Thereafter, the exhaust pipe connected to the capsule is closed and sealed. By the vacuum degassing treatment, it is possible to sufficiently remove the gas adhering to the raw material, adsorbed moisture, and the like. The heating temperature is preferably about 100 to 600 占 폚.

The vacuum degassed capsules are treated using an HIP apparatus. Capsule HIP treatment is carried out for 1 to 4 hours under conditions of 900 to 1400 deg. C and 50 MPa or more using a high-temperature, high-pressure gas as a pressure medium in the sintering process. The gas used as the pressure medium is, for example, an inert gas which does not react with the capsule, and preferably nitrogen or argon.

C., preferably not more than 200.degree. C./hr, more preferably not more than 150.degree. C./hr, and even more preferably not more than 100.degree. C./hr in the cooling process after the sintering process until the temperature in the HIP device reaches about 200.degree. Lt; RTI ID = 0.0 > cooling < / RTI > According to Boyle Charles's law, when the temperature drops, the pressure also drops. Therefore, when the capsule is rapidly cooled, the pressure also drops sharply, and cracks and cracks are likely to occur in the sintered body. When the temperature in the HIP apparatus drops below 200 DEG C, degassing in the HIP apparatus is performed, and the pressure in the capsule is returned to the atmospheric pressure.

The sintered body obtained by the method of (1), (2) or (3) may be annealed. When the annealing treatment is performed, the oxygen deficiency is generated in the sintered body, and the resistivity is lowered. Examples of the atmosphere for carrying out the annealing treatment include the above-mentioned vacuum, inert atmosphere or reducing atmosphere. Examples of the annealing method include a method of heating the sintered body at normal pressure while introducing a non-oxidizing gas such as nitrogen, argon, helium, carbon dioxide, hydrogen, or the like, or a method of heating the sintered body under vacuum And the like. From the viewpoint of the production cost, a method of carrying out the gas at normal pressure while introducing the non-oxidizing gas is advantageous.

The annealing temperature (heating temperature) is preferably 1000 to 1400 占 폚, and more preferably 1100 to 1300 占 폚. The annealing time (heating time) is preferably 7 to 15 hours, more preferably 8 to 12 hours. When the annealing temperature is lower than 1000 占 폚, oxygen deficiency due to the annealing treatment may become insufficient. On the other hand, when the annealing temperature exceeds 1400 占 폚, zinc tends to vaporize and the composition of the obtained sintered body ) May be different from the desired ratio.

The sintered body of the present invention is used as a target in various film forming methods. In particular, it is used as a target in a sputtering method, an ion plating method, a pulsed laser deposition (PLD) method, or an electron beam (EB) deposition method. The solid material to be used in such a film forming process may be referred to as a " tablet " in the present invention, but these materials are referred to as " target " Hereinafter, the sintered body obtained by processing the sintered body obtained by the manufacturing method of the present invention described above to a predetermined shape and predetermined dimensions is referred to as " target " and is distinguished from the sintered body before processing. However, since the target is also a form of the sintered body, the " sintered body "

The method of processing the sintered body is not particularly limited, and a suitably known method may be employed. For example, the target can be obtained by subjecting the sintered body to plane grinding or the like, cutting it into a predetermined dimension, and attaching (sticking) to the support. If necessary, a plurality of divided sintered bodies may be arranged to form a large-area target (composite target).

The target is used for film formation by a sputtering method, an ion plating method, a PLD method, or an EB evaporation method. As for the specific method and condition at that time, there is no particular limitation, except that the above-described target is used, and the well-known methods and conditions of the sputtering method, the ion plating method, the PLD method, or the EB deposition method may be appropriately employed.

Examples of the sputtering method include a DC sputtering method, an RF sputtering method, an AC sputtering method, a DC magnetron sputtering method, an RF magnetron sputtering method, and an ion beam sputtering method. Of these, the DC sputtering method is preferable because a large-area film can be produced uniformly and at a high speed.

The temperature of the substrate used for sputtering is not particularly limited and is affected by the heat resistance of the substrate. For example, in the case of using a non-alkali glass as a substrate, it is usually 250 DEG C or lower, and when a resin film is used as a substrate, it is usually 150 DEG C or lower. When a substrate having excellent heat resistance such as quartz, ceramics, or metal is used, the film may be formed at a temperature higher than that.

The zinc oxide based transparent conductive film of the present invention formed using the sintered body of the present invention has excellent conductivity and is excellent in light transmittance not only in the visible region (400 to 800 nm) but also in the near infrared region (800 to 2500 nm) (Heat resistance and heat resistance). Therefore, transparent electrodes such as a liquid crystal display, a plasma display, an inorganic EL (electroluminescence) display, an organic EL display, and an electronic paper; A window electrode of a photoelectric conversion element of a solar cell; An electrode of an input device such as a transparent touch panel; An electromagnetic shielding film of an electronic shield; A transparent electromagnetic wave absorber; An ultraviolet absorber; Further, it can be used in combination with another metal film / metal oxide film as a transparent semiconductor device.

In particular, by using the zinc oxide-based transparent conductive film of the present invention for a solar cell, it is possible to effectively use solar energy in the near infrared region which is insufficient in the prior art, and to provide a solar cell with high photoelectric conversion efficiency.

(Solar cell)

The zinc oxide-based transparent conductive film of the present invention is excellent in transparency not only in the visible region (400 to 800 nm) but also in the near infrared region (800 to 2500 nm), and also has low resistance and chemical durability ), It is preferably used as a material for solar cells (for example, compound solar cells, silicon solar cells, and the like).

A compound solar cell generally consists of a heterojunction of a compound semiconductor thin film having a wide band gap (an intermediate layer made of an n-type semiconductor) and a compound semiconductor thin film having a narrow band gap (a light absorbing layer made of a p-type semiconductor). The use of the n-type semiconductor as the intermediate layer and the use of the p-type semiconductor as the light absorbing layer means that a p-type semiconductor thin film having a suitable wide band gap (> 2.4 eV) is rarely present in the intermediate layer of the solar cell, This is because the diffusion length is longer for electrons.

The conditions required to achieve higher energy conversion efficiencies are to produce optically optimal designs to obtain more photocurrent and high quality heterojunctions and thin films without carrier recombination at the interface or especially in the absorber layer. A high quality heterointerface is deeply related to the combination of the intermediate layer and the light absorbing layer, and a useful heterojunction is obtained in the CdS / CdTe system, the CdS / CuInSe ₂ system, the CdS / Cu (In, Ga) Se ₂ system and the like.

An embodiment of the compound system solar cell according to the present invention is a compound semiconductor solar cell comprising a light absorbing layer made of a p-type semiconductor, an intermediate layer made of an n-type semiconductor, and a light absorbing layer made of an n-type semiconductor on a substrate on which an electrode layer is formed, A window layer, and a transparent conductive film layer made of the above-mentioned zinc oxide-based transparent conductive film are laminated in this order. Examples of the substrate include a polyimide substrate, a glass substrate, and a stainless steel substrate.

In another embodiment of the compound-based solar cell according to the present invention, a transparent electrode layer made of a transparent conductive film of zinc oxide based oxide, a window layer made of an n-type semiconductor, an intermediate layer made of an n-type semiconductor, And a metal electrode are laminated in this order. Examples of the transparent substrate include a polyimide substrate and a glass substrate.

As a material for forming the light absorbing layer made of the p-type semiconductor, for example, CuInSe ₂ , CuInS ₂ , CuGaSe ₂ , CuGaS ₂ , solid solution thereof, CdTe and the like can be given. In addition, CuZnS ₂ , CuSnS ₂ , CuZnSe ₂ , CuSnSe _2, and their solid solutions do not contain rare metals such as indium and gallium, and thus application to next-generation solar cells is expected.

Examples of the material for forming the intermediate layer made of the n-type semiconductor include CdS, In ₂ S ₃ , In (S, OH) _x , and the like.

Examples of the material for forming the window layer made of the n-type semiconductor include ZnO, Zn (O, S, OH) _x and the like.

On the other hand, the silicon-based solar cell is classified into a single crystal silicon solar cell, a polycrystalline silicon solar cell, a microcrystalline silicon solar cell, and an amorphous silicon solar cell depending on the crystal system of silicon used for the light absorption layer.

The silicon-based solar cell of the present invention is a solar cell in which a first electrode layer, a light absorbing layer and a second electrode layer are laminated in this order, and the photovoltaic power is generated by the light incident from the second electrode layer side, , And at least the second electrode layer is made of the zinc oxide-based transparent conductive film of the present invention.

The first electrode layer and the light absorbing layer are not particularly limited as long as at least the second electrode layer is made of the transparent oxide conductive film of the present invention.

A substrate is used for laminating the first electrode layer, the light absorbing layer and the second electrode layer, but examples of the substrate include a polyimide substrate, a glass substrate, and a stainless steel substrate.

As the first electrode layer, for example, a metal film electrode made of silver, aluminum, copper, molybdenum or the like is used. It is also possible to use a conductive oxide layer such as a zinc oxide thin film or a tin oxide thin film to which gallium or the like is added, if necessary, in combination with these metal film electrodes or separately. Of course, the zinc oxide based transparent conductive film of the present invention may be used.

The light absorbing layer is preferably made of an amorphous silicon type, a polycrystalline silicon type, or a microcrystalline silicon type.

If necessary, a metal interdigital electrode made of, for example, silver, aluminum, copper, molybdenum or the like may be formed on the second electrode layer.

In the silicon-based solar cell of the present invention, in one embodiment of the light absorbing layer, a p-type semiconductor (p-layer), an i-type semiconductor (i-layer) and an n- Layer) are laminated on the substrate (first embodiment).

The material of the p-layer is hydrogenated amorphous silicon carbide (a-SiC: H).

As the material of the i-layer, hydrogenated amorphous silicon (a-Si: H), crystalline silicon (c-Si), microcrystalline silicon (μc-Si) and hydrogenated amorphous silicon germanium (a-SiGe: H) . Of these, hydrogenated amorphous silicon (a-Si: H) is preferable.

Examples of the n-layer material include hydrogenated amorphous silicon (a-Si: H) and microcrystalline silicon (μc-Si). Of these, hydrogenated amorphous silicon (a-Si: H) is preferable.

As another example, a tandem-structured electroless layer on which a separate p-i-n layer is formed on the p-i-n layer of a-Si is preferably used. More preferably, the layer formed on the pin layer of amorphous silicon (a-Si) is an a-Si: H layer as a p-layer, a microcrystalline Si layer as an i- A tandem structure mechanism in which the three layers formed in this order or the three layers in which the a-Si: H layer as the p-layer, the a-SiGe: H layer as the i-layer and the a- Layer. By using the tandem-shaped electromechanical conversion layer as the photoelectric conversion layer, not only the short wavelength but also the photoelectric conversion of the long-wavelength side can be performed. Therefore, when the above- The effect of improving the photoelectric conversion efficiency becomes clearer as compared with the case of using the conventional AZO that absorbs the light of the light source.

The first embodiment is an example of a substrate-type silicon-based solar cell having a back-side electrode formed on the substrate side. However, this embodiment is different from the silicon-based solar cell in that the light- The present invention can be suitably applied to the super straight type. In this case, it is preferable to use a transparent substrate such as a glass substrate as the substrate, and use the zinc oxide-based transparent conductive film of the present invention as the first electrode layer. The first embodiment may also be applied to various types of conventionally known silicon-based solar cells, such as a lamination of a p-type semiconductor layer and an n-type semiconductor layer in this order from the first electrode layer side.

As another embodiment of the light absorbing layer, a photoelectric conversion unit in which an n-type semiconductor layer, an i-type semiconductor layer, a single crystal or polycrystalline silicon, an i-type semiconductor layer and a p-type semiconductor layer are stacked in this order from the first electrode layer side (Second embodiment). A solar cell in which this type of photoelectric conversion unit is used is called a heterojunction solar cell.

In the second embodiment, an i-type semiconductor layer and an n-type semiconductor layer are sequentially formed on one surface (a side other than the light-receiving portion) of a single crystal or polycrystalline silicon, and a first electrode layer is formed on the n- . An i-type semiconductor layer and a p-type semiconductor layer are sequentially formed on the other surface (on the light-receiving portion side) of the single crystal or polycrystalline silicon and a zinc oxide-based transparent conductive film of the present invention is formed as a second electrode layer on the p- In some cases, a metal interdigital electrode may be formed on the second electrode layer as in the first embodiment.

Next, examples of the electrode material of the back electrode layer include metals containing Ag or an Ag alloy, Al, or an Al alloy as a main component. Preferably, the back electrode layer is made of a metal film containing at least 95 mol% of crystalline Ag in the film. By using the crystalline Ag in the metal film of the back electrode, it is possible to reflect the light transmitted through the light absorbing layer, and to return the reflected light back to the light absorbing layer again, leading to an effect of improving photoelectric conversion efficiency.

Examples of the single crystal or polycrystalline silicon include an n-type silicon wafer and a p-type silicon wafer. The first electrode layer and the n-type semiconductor, the i-type semiconductor, and the p-type semiconductor in the second embodiment are the same as those in the first embodiment.

The method of forming each layer in each of the above-described embodiments and the film thickness of each layer are not particularly limited and conventionally known methods may be appropriately performed.

The sheet resistance required for the transparent conductive film for a solar cell is about 10? / ?. Solar cells are typically used in the form of integrated modules in which solar cells are connected in series. Therefore, the sheet resistance required for the transparent conductive film is preferably lower than that of a single cell, but in the form actually used (solar cell module), an area loss occurs due to the number of cells connected in series . As the number of series connection stages of the cells increases, the area loss increases. In addition, a line loss due to the contact resistance between the transparent conductive film and the back electrode also occurs. This also increases as the number of series connection stages increases and the number of contact portions increases. Therefore, if the area loss and the line loss due to the contact resistance between the transparent conductive film and the back electrode are larger than the line loss caused by the transparent conductive film and the sheet resistance of the transparent conductive film is about 10? / Square, Even if the resistance is smaller than this, the influence on the conversion efficiency of the solar cell is slight. The area loss and the line loss due to the contact resistance between the transparent conductive film and the back electrode are dominant factors.

It is also known that the currently used zinc oxide based transparent conductive film (AZO) has a dependency of the resistivity on the film thickness. The thicker the film thickness, the lower the resistivity, and the resistivity gradually decreases to about 500 nm. Even if the film thickness is thicker than 500 nm, the resistivity takes a constant value. Since AZO has a dependence of the resistivity on the film thickness, it is necessary to have a film thickness of at least 500 nm in order to realize 10 Ω / □. For this reason, in the zinc oxide based transparent conductive film, the film thickness is 500 nm and the sheet resistance is 10 Ω / □ or less. It is preferable that the zinc oxide-based transparent conductive film of the present invention has a sheet resistance of 10 Ω / □ or less at a film thickness of 500 nm, and more preferably 9 Ω / □ or less.

In addition, while solar cells are used outdoors, AZO and GZO lack chemical durability and solar cells using them are inferior in durability. On the other hand, the zinc oxide-based transparent conductive film of the present invention has excellent chemical durability (heat and humidity resistance and heat resistance), and solar cells using such a transparent conductive film also have excellent chemical durability (heat and humidity resistance and heat resistance).

In addition, although a compound solar cell and a silicon solar cell are described as solar cells as an example, a gallium arsenide-based solar cell, an organic solar cell using an organic material, and the like may also be used as the electrode layer on the light- .

Example

Hereinafter, the present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to these examples.

The evaluation of properties in Examples and Comparative Examples is as follows.

<Resistivity>

The specific resistance was measured by a 4-terminal 4 probe method using a resistivity meter ("LORESTA-GP, MCP-T610" manufactured by Mitsubishi Chemical Corporation). Specifically, the resistance was obtained by measuring the potential difference generated between the inner two probes by flowing a constant current between the two probes between the outer two probes and the inner one, with four needle electrodes on the sample in a straight line.

<Surface resistance>

The surface resistance (Ω / □) was calculated by dividing the resistivity (Ω · cm) by the film thickness (㎝). The film thickness was measured using "Alpha-Step IQ" manufactured by Tencor Corporation.

<Mobility and carrier electron concentration>

The mobility and carrier electron concentration were measured by the HALL effect measurement method by the Van Der Pauw method. For the measurement, a probe having a tip of 250 탆 phi was used by using a HL5500PC Hall effect measuring apparatus manufactured by Nanometrics Inc.

<Relative density>

Relative density was obtained by the following equation.

Relative density = 100 x [(density of sintered body) / (theoretical density)]

The theoretical density was obtained by the following method. First, the density of each component used in the production of the sintered body is multiplied by the ratio of the weight of the components when the total weight of the components used for manufacturing the sintered body is 1. This was calculated for all the used components, and the sum of them was made the theoretical density.

The density of the sintered body was determined by the following method. The sintered body was processed into a square shape or a cylindrical shape so that an accurate volume could be measured. The volume and the weight of the processed sintered body were measured. From the volume and weight of the sintered body thus measured, the density of the sintered body was determined according to the following formula.

Density of the sintered body (g / cm3) = [(weight of the sintered body) / (volume of the sintered body)]]

Hereinafter, the method may be referred to as a measurement method.

<Color difference measurement>

The surface of the sintered body was wet-polished by a wet grinding machine (Marutopra Co., Ltd., Maruto Co., Ltd.) using the abrasive paper # 60 and # 180 until the surface roughness Ra became 0.5 m or less. The chromaticity a *, chromaticity b * and lightness L * of the surface were measured using a spectroscopic colorimeter (Z-300A, Nippon Denshoku Kogyo Co., Ltd.) and evaluated in the CIE 1976 space. The measurement results of the sintered bodies obtained in the respective Examples and Comparative Examples are shown in Table 3.

<Transmittance>

The transmittance was measured in a visible region (400 nm to 800 nm) and near infrared region (800 nm to 1400 nm and 800 nm to 2500 nm) using an ultraviolet visible near infrared spectrophotometer ("V-670" &Lt; / RTI &gt; nm). Further, the transmittance of a transparent conductive substrate including a glass substrate was measured.

<Humidity Durability>

The transparent conductive film was subjected to a moisture resistance heat test in which the temperature was maintained at 85 캜 and 85% relative humidity for 1000 hours, and the surface resistance was measured. The value of (B-A) / A was determined in units of% when the surface resistance before the test was A and the surface resistance after the test was B, which was used as an index of resistance to humidity resistance. The larger the value, the greater the surface resistance after the test.

<Heat resistance>

The transparent conductive substrate was subjected to a heat resistance test in which the temperature was maintained at 300 캜 for 2,000 minutes in the atmosphere, and then the surface resistance was measured. The value of (B-A) / A was determined in units of% when the surface resistance before the test was A and the surface resistance after the test was B, and the index was taken as an index of heat resistance. The larger the value, the greater the surface resistance after the test. When the value is a negative number, it indicates that the surface resistance after the test is smaller than that before the test. The smaller the value, the better the heat resistance.

(Example 1)

(Purity: 99.9%, average primary particle size: 1 占 퐉 or less) and titanium monoxide powder (TiO (II): manufactured by Furuuchi Chemical Co., Ltd., purity: 99.9% Average primary particle size of 1 mu m or less) were weighed in a total amount of 100 g so that the atomic ratio of zinc and titanium was Zn: Ti = 98.2: 1.8. Subsequently, 50 g of ethanol was added as a solvent and wet-mixed by a wet ball mill mixing method. This wet mixing was carried out for 18 hours using a hard ZrO ₂ ball (2 mmφ) as a ball. Subsequently, the slurry after the wet mixing was taken out, the balls were removed by sieving, the mixed solvent was removed by a distributor, and the residue was dried at 100 ° C for 3 hours by a hot air drier to obtain a mixed powder.

The obtained mixed powder was put into a mold (dice) made of graphite having a diameter of 100 mm. Vacuum pressurized at 30 MPa with a punch made of graphite, and subjected to a heat treatment (hot press (HP) method) at 1000 占 폚 for 4 hours to obtain a disc-shaped sintered body. The theoretical density of the sintered body was 5.59 g / cm 3, and the relative density was 97.9%. The theoretical density was obtained as follows.

Theoretical density = (density of zinc oxide x mixed mass ratio) + (density of titanium monoxide x mixed mass ratio)

           = 5.6 x 0.982 + 4.93 x 0.018

           = 5.59

The sintered body was subjected to surface grinding, outer grinding and surface grinding to obtain a disk-shaped oxide sintered body having a diameter of 80 mm and a thickness of 3 mm. The obtained oxide-sintered body was bonded with indium solder using a copper plate as a backing plate to obtain a sputtering target.

Using the obtained sputtering target, a transparent oxide conductive film was formed on the substrate to have a film thickness of about 500 nm by sputtering under the following conditions. In sputtering for about 50 minutes, the number of times of stopping the operation of the sputtering apparatus due to the abnormal discharge was 3 or less, and the sputtering rate was 10 nm / min, and the deposition stability was good.

Target dimensions: diameter 80 mm, thickness 3 mm

Sputtering apparatus: Small sputtering apparatus CS-L manufactured by ULVAC CO., LTD.

Sputtering method: DC magnetron sputtering

Achieved vacuum degree: 1.0 × 10 ^-4 Pa or less

Sputtering gas: argon

Sputtering gas pressure: 1.0 Pa

Substrate temperature: 200 DEG C

Duration: about 50 minutes

Sputter power: 200 W (3.98 W / cm 2)

Substrate used: Alkali glass (100 mm x 100 mm x 0.7 mm)

The thin film thus obtained was dissolved in hydrochloric acid twice diluted with commercially available concentrated hydrochloric acid, and the composition of the thin film was analyzed by ICP-AES (Thermo-6500, manufactured by Thermo Fisher Scientific Co., Ltd.). A thin film having substantially the same composition as the target composition was obtained.

The transparent conductive film was subjected to X-ray diffraction using an attachment for thin-film measurement using an X-ray diffraction apparatus (RINT2000, manufactured by Rigaku Denki Co., Ltd.) (TEM-EDX) was used to investigate the doping state of titanium to zinc, and the crystal structure was further investigated using an electric field-type electron microscope (FE-SEM). As a result, it was found that the single phase of the C-axis oriented Wurtzite type was replaced by titanium and substituted by zinc.

The carrier electron density, the mobility, the resistivity, the surface resistance, the humidity resistance and the heat resistance were measured for the transparent conductive film on the obtained transparent conductive substrate. Carrier electron concentration of 3.17 × 10 ²⁰ ㎝ ^{- 3,} and the mobility is 44.7 ㎠ / Vs, and the specific resistance of 4.4 × 10 ^-4 Ω · ㎝ and, and surface resistance of 9.1 Ω / □ (thickness 483 ㎚, thickness Was set to 500 nm, the resistance was 8.8? /?). Thus, the obtained transparent conductive film had low resistance. The results are shown in Table 2.

The transmittance (including the glass substrate) of the obtained transparent conductive substrate was 82.1% on average in the visible region (400 nm to 800 nm), 80.8% on average in the near infrared region of 800 nm to 1400 nm, In the near infrared region, the mean was 53.6%. The change in resistance in the resistance to humidity test was 12%. The change in resistance in the heat resistance test was -7.1%, and the resistance value after the test was lower than that before the test. The results are shown in Table 2.

(Example 2)

The same zinc oxide powder and titanium monoxide powder as in Example 1 were used so that the raw material composition shown in Table 1 was obtained. Aluminum oxide powder having a purity of 99.9% and an average primary particle size of 0.5 mu m Sputtering target was obtained in the same manner as in Example 1 except that the raw material powder composed of ₂ O ₃ powder was used.

Using the obtained sputtering target, a transparent conductive oxide film based on zinc oxide was formed on the substrate to have a film thickness of about 500 nm under the same conditions as in Example 1 by sputtering.

In the case of using any sputtering target, the number of times of stopping the operation of the sputtering apparatus due to the abnormal discharge was within 3 times in the sputtering for about 50 minutes, the sputtering rate was about 10 nm / min, and the film forming stability was good .

The thin film compositions were analyzed in the same manner as in Example 1 for each of the obtained thin films. All thin films had almost the same composition as the target composition.

The obtained thin films were each subjected to X-ray diffraction using an X-ray diffraction apparatus (RINT2000 manufactured by Rigaku Denki Co., Ltd.) using an attachment for thin-film measurement in the same manner as in Example 1, The dope state of titanium on zinc was examined using an X-ray microanalyzer (TEM-EDX), and the crystal structure was further investigated using a field-emission-type electron microscope (FE-SEM). As a result, it was found that all of them were single-phase of Wurtz-type with C-axis alignment and titanium was substituted with zinc.

The carrier electron density, the mobility, the resistivity, the surface resistance, the humidity resistance and the heat resistance were measured for the transparent conductive film on the obtained transparent conductive substrate. The results are shown in Table 2. The transmittance (including the glass substrate) of each of the obtained transparent conductive substrates was measured (visible region and near infrared region). The resistance change in the resistance to humidity test was 48%. The change in resistance in the heat resistance test was -0.8%, and the resistance value after the test was lower than that before the test. The results are shown in Table 2.

(Examples 3, 4, 7 and 8, and Comparative Examples 1 to 11)

The same raw material powder as that used in Example 1 or Example 2 was used so that the raw material composition shown in Table 1 was used, and a sintered body was obtained by a discharge plasma sintering (SPS) method instead of the hot pressing method. A sputtering target was obtained in this order. The discharge plasma sintering was carried out as follows. The obtained mixed powder was put into a die made of graphite and pressurized in a Ar atmosphere at a pressure of 30 MPa with a punch made of graphite having a diameter of 100 mm. Thereafter, the temperature was raised from room temperature to a sintering temperature (1000 캜) for about 30 minutes, and SPS (discharge plasma sintering) treatment was performed at 1000 캜 for 15 minutes to obtain a disc-shaped sintered body.

Using each of the obtained sputtering targets, a zinc oxide based transparent conductive film was formed on the substrate to have a film thickness of about 500 nm under the same conditions as in Example 1 by sputtering. In the case of using any sputtering target, the number of times of stopping the operation of the sputtering apparatus due to the abnormal discharge was within 3 times in the sputtering for about 50 minutes, the sputtering rate was about 10 nm / min, and the film forming stability was good .

The thin film compositions were analyzed in the same manner as in Example 1 for each of the obtained thin films. All thin films had almost the same composition as the target composition.

The obtained thin films were each subjected to X-ray diffraction using an X-ray diffraction apparatus (RINT2000 manufactured by Rigaku Denki Co., Ltd.) using an attachment for thin-film measurement in the same manner as in Example 1, The dope state of titanium on zinc was examined using an X-ray microanalyzer (TEM-EDX), and the crystal structure was further investigated using an electric field-type electron microscope (FE-SEM). As a result, it was found that all of them were single-phase of Wurtz-type with C-axis alignment and titanium was substituted with zinc.

The carrier electron concentration, the mobility, the specific resistance, the surface resistance, the humidity resistance and the heat resistance were measured for each of the transparent conductive films on the obtained transparent conductive substrate. The results are shown in Table 2. The transmittance (including the glass substrate) of each of the obtained transparent conductive substrates was measured (visible region and near infrared region). The results are shown in Table 2.

(Example 5)

Instead of the hot press (HP) method, titanium dioxide trioxide powder (Ti ₂ O ₃ (III): manufactured by Furuuchi Chemical Co., Ltd., purity of 99.9%, average primary particle size of 1 μm or less) A sputtering target was obtained in the same manner as in Example 2 except that a sintered body was obtained by the capsule HIP sintering method. The capsule HIP sintering was carried out as follows.

First, the raw material powder was dry-mixed at a ratio of atomic ratio of Zn: Ti: Al of 98.2: 1.0: 0.8 to obtain a mixed powder. The obtained mixed powder was heated from room temperature to 1200 占 폚 at a temperature raising rate of 10 占 폚 / min in an inert atmosphere (Ar), and then calcined at 1200 占 폚 for 10 hours. After firing, the mixture was lightly hand crushed by induction to obtain a zinc oxide-based powder. The tap density of the resulting zinc oxide-based powder was determined in accordance with JIS K5101. That is, the zinc oxide powder was charged while imparting vibration until the volume change of the zinc oxide powder was eliminated in the measuring cylinder of a predetermined size, and the volume (cm 3) of the measuring cylinder and the filling amount (g) of the zinc oxide powder were obtained. The obtained zinc oxide-based powder had a tap density of 3.12 g / cm 3.

Next, the obtained zinc oxide-based powder was vibrated in a container made of stainless steel (SUS304) (outer diameter: 103 mm, inner diameter: 100 mm, height: 78 mm) until the volume change of the zinc oxide- . The tap density of the zinc oxide-based powder was 3.12 g / cm 3, and the packing density was about 55.7% in that the theoretical density was about 5.6 g / cm 3.

The theoretical density was obtained by the following formula.

Theoretical density = (density of zinc oxide x mixed mass ratio) + (density of titanium trioxide x mixed mass ratio) + (density of aluminum oxide x mixed mass ratio)

After filling the metal container with the zinc oxide-based powder, the exhaust pipe was welded to the upper cover of the metal container, and then the upper cover and the metal container were welded. In order to confirm the integrity of the welded part of the metal container, a He leak test was carried out. At this time, the amount of leakage was set to 1 x 10 &lt; ^-9 &gt; Pa · m &lt; 3 &gt; / sec or less. Next, the inside of the metal container was depressurized for 7 hours while being heated to 550 占 폚, confirming that the metal container had reached 1.33 占^10-2 Pa or less, closed the exhaust pipe, and sealed the metal container. The encapsulated metal container was placed in a HIP apparatus (manufactured by Kobe Steel Co., Ltd.), and subjected to capsule HIP treatment. Capsule HIP treatment was carried out at 1100 占 폚 for 1 hour using argon (Ar) gas (purity 99.9%) at a pressure of 100 MPa as a pressure medium. After the HIP treatment, the metal vessel was separated to obtain a cylindrical sintered zinc oxide-based sintered body.

The sintered zinc oxide-based sintered body was observed with an electron microscope, and it was a dense sintered body having little vacancy. The relative density of the sintered zinc oxide-based sintered body was 98.9% as determined by the following equation. The theoretical density was as described above, and the density of the sintered body was determined by the lateral method.

Relative density = [(density of sintered body) / (theoretical density)] x 100

The zinc oxide-based sintered body was subjected to surface grinding, external grinding and surface grinding to obtain a disk-shaped oxide sintered body having a diameter of 80.0 mm and a thickness of 3 mm. The obtained oxide-sintered body was bonded with indium solder using a copper plate as a backing plate to obtain a sputtering target.

Using the obtained sputtering target, a transparent conductive oxide film based on zinc oxide was formed on the substrate to have a film thickness of about 500 nm under the same conditions as in Example 1 by sputtering. In sputtering for about 50 minutes, the number of times of stopping the operation of the sputtering apparatus due to the abnormal discharge was 3 or less, and the sputtering rate was about 10 nm / min, and the deposition stability was good.

The obtained thin film was analyzed for the thin film composition in the same manner as in Example 1, and the composition was almost the same as the target composition.

The obtained thin film was subjected to X-ray diffraction using an X-ray diffraction apparatus (RINT2000 manufactured by Rigaku Denki Co., Ltd.) in the same manner as in Example 1, using an attachment for thin-film measurement, The doping state of titanium to zinc was examined using a line micro-analyzer (TEM-EDX), and the crystal structure was further investigated using an electric field-type electron microscope (FE-SEM). As a result, it was found that the single phase was a wurtzite type crystal aligned in the C axis, and titanium was substituted by zinc.

The carrier electron density, the mobility, the resistivity, the surface resistance, the humidity resistance and the heat resistance were measured for the transparent conductive film on the obtained transparent conductive substrate. The results are shown in Table 2. The transmittance (including the glass substrate) of the obtained transparent conductive substrate was measured (visible region and near infrared region).

The results are shown in Table 2.

(Example 6)

A sputtering target was obtained in the same manner as in Example 5 except that a titanium black powder (manufactured by Mitsubishi Materials Corporation, part number &quot; 13M &quot;, primary particle size: 97 nm) was used instead of titanium trioxide powder to obtain a sintered body.

Using the obtained sputtering target, a transparent conductive oxide film based on zinc oxide was formed on the substrate to have a film thickness of about 500 nm under the same conditions as in Example 1 by sputtering. In sputtering for about 50 minutes, the number of times of stopping the operation of the sputtering apparatus due to the abnormal discharge was 3 or less, and the sputtering rate was about 10 nm / min, and the deposition stability was good.

The obtained thin film was analyzed for the thin film composition in the same manner as in Example 1, and the composition was almost the same as the target composition.

The obtained thin film was subjected to X-ray diffraction using an X-ray diffraction apparatus (RINT2000 manufactured by Rigaku Denki Co., Ltd.) in the same manner as in Example 1, using an attachment for thin-film measurement, The doping state of titanium to zinc was examined using a line micro-analyzer (TEM-EDX), and the crystal structure was further investigated using an electric field-type electron microscope (FE-SEM). As a result, it was found that the single phase was a wurtzite type crystal aligned in the C axis, and titanium was substituted by zinc.

The carrier electron density, the mobility, the resistivity, the surface resistance, the humidity resistance and the heat resistance were measured for the transparent conductive film on the obtained transparent conductive substrate. The results are shown in Table 2. The transmittance (including the glass substrate) of the obtained transparent conductive substrate was measured (visible region and near infrared region).

The results are shown in Table 2.

(Example 9)

(Ga ₂ O ₃ : Sumitomo Chemical Co., Ltd.) was used instead of the aluminum oxide powder by using a titanium carbide powder (TiC: manufactured by Nippon Shin Metal Co., Ltd., purity: 99.9%, average particle size: 0.9 to 1.5 탆) A sputtering target was obtained in the same manner as in Example 2 except that a sintered body was obtained by a discharge plasma sintering method instead of the hot pressing method by using a pelletizing machine (purity: 99.9%, average particle diameter: 1 μm or less). The conditions of the discharge plasma sintering method are the same as those of the third embodiment.

Using the obtained sputtering target, a transparent conductive oxide film based on zinc oxide was formed on the substrate to have a film thickness of about 500 nm under the same conditions as in Example 1 by sputtering. In sputtering for about 50 minutes, the number of times of stopping the operation of the sputtering apparatus due to the abnormal discharge was 3 or less, and the sputtering rate was about 10 nm / minute, and the deposition stability was good.

The obtained thin film was analyzed for the thin film composition in the same manner as in Example 1, and the composition was almost the same as the target composition.

The obtained thin film was subjected to X-ray diffraction using an X-ray diffraction apparatus (RINT2000 manufactured by Rigaku Denki Co., Ltd.) in the same manner as in Example 1, using an attachment for thin-film measurement, The doping state of titanium to zinc was examined using a line micro-analyzer (TEM-EDX), and the crystal structure was further investigated using an electric field-type electron microscope (FE-SEM). As a result, it was found that the single phase was a wurtzite type crystal aligned in the C axis, and titanium was substituted by zinc.

The carrier electron density, the mobility, the resistivity, the surface resistance, the humidity resistance and the heat resistance were measured for the transparent conductive film on the obtained transparent conductive substrate. The results are shown in Table 2. The transmittance (including the glass substrate) of the obtained transparent conductive substrate was measured (visible region and near infrared region).

The results are shown in Table 2.

(Examples 10 to 13)

A sputtering target was obtained in the same manner as in Example 5 except that the raw material powder shown below was used to obtain a sintered body.

Example 10 Titanium nitride powder (TiN: product number "TiN-01", manufactured by Nippon Shinku Co., Ltd., average primary particle size 1.0 to 1.5 탆) was used as a titanium source, Was used.

Example 11 Titanium monoxide powder used in Example 1 was used as the titanium source and aluminum carbide (Al ₄ C ₃ : manufactured by Kojundo Chemical Co., Ltd., purity: 99.9%, average particle diameter: 0.5 μm) was used as the aluminum source Respectively.

Example 12: Titanium dioxide powder used in Example 5 was used as the titanium source, and aluminum nitride (AlN: manufactured by Wako Pure Chemical Industries, Ltd., purity: 99.9%, average particle diameter: 50 nm) was used as the aluminum source .

Example 13: Titanium dioxide powder used in Example 5 was used as the titanium source, and gallium nitride (GaN: manufactured by Kojundo Chemical Co., Ltd., purity: 99.9%, average particle diameter: 0.5 탆) was used as a gallium source.

Using each of the obtained sputtering targets, a zinc oxide based transparent conductive film was formed on the substrate to have a film thickness of about 500 nm under the same conditions as in Example 1 by sputtering. In the case of using any sputtering target, the number of times of stopping the operation of the sputtering apparatus due to the abnormal discharge was within 3 times in the sputtering for about 50 minutes, the sputtering rate was about 10 nm / min, and the film forming stability was good .

The thin film compositions were analyzed in the same manner as in Example 1 for each of the obtained thin films. All thin films had almost the same composition as the target composition.

The obtained thin films were each subjected to X-ray diffraction using an X-ray diffraction apparatus (RINT2000 manufactured by Rigaku Denki Co., Ltd.) using an attachment for thin-film measurement in the same manner as in Example 1, The dope state of titanium on zinc was examined using an X-ray microanalyzer (TEM-EDX), and the crystal structure was further investigated using an electric field-type electron microscope (FE-SEM). As a result, it was found that all of them were single-phase of Wurtz-type with C-axis alignment and titanium was substituted with zinc.

The carrier electron concentration, the mobility, the specific resistance, the surface resistance, the humidity resistance and the heat resistance were measured for each of the transparent conductive films on the obtained transparent conductive substrate. The results are shown in Table 2. The transmittance (including the glass substrate) of each of the obtained transparent conductive substrates was measured (visible region and near infrared region). The results are shown in Table 2.

(Comparative Example 12)

Except that a sintered body was obtained by using titanium boride powder (TiB ₂ : manufactured by Nippon Shin Metal Co., Ltd., product number "TiB ₂ -NF", purity of 99.9%, average particle size of 1.0 to 2.0 μm) instead of titanium trioxide powder, A sputtering target was obtained in the same manner as in Example 5.

Using the obtained sputtering target, a transparent conductive oxide film based on zinc oxide was formed on the substrate to have a film thickness of about 500 nm under the same conditions as in Example 1 by sputtering.

In sputtering for about 50 minutes, the number of times of stopping the operation of the sputtering apparatus due to the abnormal discharge was 3 or less, and the sputtering rate was about 10 nm / minute, and the deposition stability was good.

The obtained thin film was analyzed for the thin film composition in the same manner as in Example 1, and the composition was almost the same as the target composition.

The obtained thin film was subjected to X-ray diffraction using an X-ray diffraction apparatus (RINT2000 manufactured by Rigaku Denki Co., Ltd.) in the same manner as in Example 1, using an attachment for thin-film measurement, The doping state of titanium to zinc was examined using a line micro-analyzer (TEM-EDX), and the crystal structure was further investigated using an electric field-type electron microscope (FE-SEM). As a result, it was found that the single phase was a wurtzite type crystal aligned in the C axis, and titanium was substituted by zinc.

The carrier electron density, the mobility, the resistivity, the surface resistance, the humidity resistance and the heat resistance were measured for the transparent conductive film on the obtained transparent conductive substrate. The results are shown in Table 2. The transmittance (including the glass substrate) of the obtained transparent conductive substrate was measured (visible region and near infrared region).

The results are shown in Table 2.

(Comparative Example 13)

A sputtering target was obtained in the same manner as in Example 5 except that a titanium dioxide powder (TiO ₂ : manufactured by High Purity Chemical Laboratories, purity: 99.9%, average particle diameter: 0.5 to 1.0 μm) was used instead of titanium trioxide powder to obtain a sintered body.

Using the obtained sputtering target, a transparent conductive oxide film based on zinc oxide was formed on the substrate to have a film thickness of about 500 nm under the same conditions as in Example 1 by sputtering.

In sputtering for about 50 minutes, the number of times of stopping the operation of the sputtering apparatus due to the abnormal discharge was 3 or less, and the sputtering rate was about 10 nm / minute, and the deposition stability was good.

The obtained thin film was analyzed for the thin film composition in the same manner as in Example 1, and the composition was almost the same as the target composition.

The obtained thin film was subjected to X-ray diffraction using an X-ray diffraction apparatus (RINT2000 manufactured by Rigaku Denki Co., Ltd.) in the same manner as in Example 1, using an attachment for thin-film measurement, The doping state of titanium to zinc was examined using a line micro-analyzer (TEM-EDX), and the crystal structure was further investigated using an electric field-type electron microscope (FE-SEM). As a result, it was found that the single phase was a wurtzite type crystal aligned in the C axis, and titanium was substituted by zinc.

The carrier electron density, the mobility, the resistivity, the surface resistance, the humidity resistance and the heat resistance were measured for the transparent conductive film on the obtained transparent conductive substrate. The results are shown in Table 2. The transmittance (including the glass substrate) of the obtained transparent conductive substrate was measured (visible region and near infrared region).

The results are shown in Table 2.

(Comparative Examples 14 to 17)

A sputtering target was obtained in the same manner as in Example 1 except that the same raw material powder as that used in the other examples and comparative examples was used so that the raw material composition shown in Table 1 was obtained. The dopant Ga ₂ O ₃ of Comparative Example 17 was manufactured by Sumitomo Chemical Co., Ltd., and had a purity of 99.9% and an average primary particle size of 0.5 탆.

AZO (Comparative Examples 14 to 16) and GZO (Comparative Example 17) were used as sputtering targets, and Comparative Examples 14 and 15 were carried out in the same manner as in Example 1 except that the substrate temperature (film forming temperature) , And a zinc oxide based transparent conductive film was formed on the substrate so as to have a film thickness of about 500 nm. In the case of using any sputtering target, the number of times of stopping the operation of the sputtering apparatus due to the abnormal discharge was within 3 times in the sputtering for about 50 minutes, the sputtering rate was about 10 nm / min, and the film forming stability was good .

The carrier electron concentration, the mobility, the specific resistance, the surface resistance, the humidity resistance and the heat resistance were measured for each of the transparent conductive films on the obtained transparent conductive substrate. The results are shown in Table 2. The transmittance (including the glass substrate) of each of the obtained transparent conductive substrates was measured (visible region (400 nm to 800 nm), near infrared region of 800 nm to 1400 nm, and near infrared region of 800 nm to 2500 nm ). The results are shown in Table 2.

As shown in Table 2, the films on the transparent conductive substrate obtained in Examples 1 to 13 were transparent conductive films having low resistance, excellent conductivity, high transparency in the near infrared region, and excellent chemical durability (heat and humidity resistance and heat resistance) .

On the other hand, the films on the transparent conductive substrate obtained in Comparative Examples 1 to 17 showed a decrease in the transmittance in the near infrared region and deterioration of the film in the heat and humidity resistance test and the heat resistance test.

(Example 14: Fabrication of compound-based thin film solar cell)

The compound thin film solar cell 1 shown in Fig. 1 was produced in the following procedure.

First, a zinc oxide-based transparent conductive film 15 having a film thickness of about 500 nm was formed on the glass substrate 16 using the target obtained in Example 1 under the same deposition conditions as in Example 1.

A ZnO thin film having a film thickness of about 150 nm was formed as a window layer 14 by a DC magnetron sputtering method (sputter gas is argon) using a ZnO target on a zinc oxide-based transparent conductive film 15.

On the window layer 14, a mixed solution of CdI ₂ , NH ₄ Cl, NH ₃ and thiourea was used to form a hetero pn junction. By using the solution precipitation method, an intermediate layer 13 made of n-type semiconductor A CdS thin film having a thickness of about 20 nm was formed. On the intermediate layer 13, by vacuum evaporation, as a light absorbing layer 12 made of p-type semiconductor to form a CuInGaSe ₂ thin film having a film thickness of about 2 ~ 3 ㎛. On the light absorbing layer 12, an Au thin film having a thickness of about 1 mu m was formed as a double metal electrode layer 11 by a vacuum vapor deposition method.

The obtained compound thin film solar cell 1 was irradiated with irradiation light of 100 mW / cm 2 from the glass substrate 16 side in an AM 1.5 (air mass 1.5), and the characteristics were investigated. Next, in order to evaluate the resistance to humidity and humidity of the obtained solar cell, the solar cell was maintained in an atmosphere at a temperature of 85 캜 and a relative humidity of 85% for 1000 hours. After 1000 hours, the transparent conductive film in the solar cell was slightly deteriorated. However, even if the conversion efficiency was measured, the transparent conductive film in the solar cell was reduced to such an extent as not to affect the performance of the solar cell. Since the compound-based thin film solar cell 1 uses the zinc oxide-based transparent conductive film of the present invention as the zinc oxide-based transparent conductive film 15, the compound-based thin film solar cell 1 has excellent moisture resistance and excellent permeability in the near infrared region , The conversion efficiency from light energy to electric energy was high.

(Comparative Example 18: Fabrication of compound-based thin film solar cell)

Based thin film solar cell was obtained in the same manner as in Example 14 except that a transparent conductive film was formed using AZO (the target obtained in Comparative Example 16) instead of the zinc oxide based transparent conductive film 15. [ The obtained compound thin film solar cell was examined in the same manner as in Example 14 for characteristics and wet heat resistance. As a result, the conversion efficiency from light energy to electric energy was much higher than that of the compound thin film solar cell (1) Low, and the heat resistance was also inferior.

Example 14 and Comparative Example 18, a light absorption layer Despite an example of a compound-based thin film solar cell using the CuInSe ₂ thin film, a light absorption layer _{CuInS 2, CuGaSe 2, Cu (} In, Ga) Se 2, Cu (In, Ga) (S, Se) ₂ , and CdTe were used, the same results were obtained.

As described above, it was found that a solar cell having a high conversion efficiency and excellent chemical durability can be manufactured by using the zinc oxide based transparent conductive film according to the present invention, as compared with the case of using a conventional transparent oxide conductive film based on zinc oxide.

(Example 15: manufacture of solar battery cell (amorphous silicon solar cell)

A p-type layer, an i-type layer and an n-type layer were formed in this order on the transparent conductive substrate obtained in Example 1 in the following procedure to form a p-i-n three-layer photoelectric conversion unit (light absorption layer).

(p-type layer)

A high purity semiconductor gas of silane (SiH ₄ ), hydrogen (H ₂ ), diborane (B ₂ H ₆ ), and methane (CH ₄ ) is transported to a p-type silicon film forming chamber Was introduced into the chamber at a constant flow rate. The substrate temperature was maintained at 150 캜 and the pressure was maintained at 0.5 Torr, and discharge was started. A boron doped a-Si alloy film having a film thickness of about 10 nm was formed on the transparent conductive substrate in one minute. Subsequently, only the introduction of B ₂ H ₆ was stopped, and a non-doped a-SiC alloy film having a film thickness of about 5 nm was formed as a solar cell buffer layer under the same conditions and under the same conditions. After the completion of the film formation, the film was evacuated again to obtain a high vacuum state.

(i-type layer)

After the transparent conductive substrate on which the p-type layer was formed was transported to the i-type silicon film formation chamber, high purity semiconductor gas of SiH ₄ and H ₂ was introduced into the i-type silicon film formation chamber at a constant flow rate. The substrate temperature was maintained at 150 占 폚 and the pressure was maintained at 1.0 Torr, and discharge was started. A non-doped a-Si alloy film having a film thickness of about 0.35 mu m was formed on the p-type layer in 25 minutes. After the completion of the film formation, the film was evacuated again to obtain a high vacuum state.

(n-type layer)

The transparent conductive substrate on which the p-type layer and the i-type layer were formed was transported to the n-type silicon film formation chamber, and high purity semiconductor gas of SiH ₄ , H ₂ and phosphine (PH ₃ ) was introduced into the i-type silicon film formation chamber at a constant flow rate. The substrate temperature was maintained at 150 캜 and the pressure was maintained at 0.2 Torr, and discharge was started. An indium a-Si alloy film having a film thickness of about 30 nm was formed on the i-type layer in 6 minutes. After the completion of the film formation, the film was evacuated again to obtain a high vacuum state.

After forming the p-i-n three-layer photoelectric conversion unit, a rear-surface reflective electrode layer was formed in the following order.

The transparent conductive substrate on which the p-i-n three-layer photoelectric conversion unit was formed was cooled to room temperature, taken out into the atmosphere, and then placed in a sputtering vacuum apparatus. At room temperature, a gallium-doped zinc oxide layer having a thickness of about 20 nm, a silver layer having a thickness of about 200 nm, and a gallium-doped zinc oxide layer having a thickness of about 20 nm were sequentially stacked in this order on a pin 3-layer photoelectric conversion unit . The solar cell (amorphous silicon solar cell) having an area of 0.25 cm 2 was obtained by patterning the back electrode, and then post-annealing at 150 캜 was performed for 2 hours.

The conversion efficiency of the obtained solar cell was measured and found to be very high. Next, in order to evaluate the resistance to humidity and humidity of the obtained solar cell, the solar cell was maintained in an atmosphere at a temperature of 85 캜 and a relative humidity of 85% for 1000 hours. After 1000 hours, the transparent conductive film in the solar cell was slightly deteriorated. However, even if the conversion efficiency was measured, the transparent conductive film in the solar cell was reduced to such an extent as not to affect the performance of the solar cell.

(Comparative Example 19: Production of solar battery cell (amorphous silicon solar cell)

A solar cell (amorphous silicon solar cell) was obtained in the same manner as in Example 15 except that a transparent conductive substrate (Comparative Example 16) in which an AZO thin film was formed was used in place of the transparent conductive substrate obtained in Example 1.

The conversion efficiency of the obtained solar cell was measured, and the conversion efficiency was lower than that of the solar cell obtained in Example 15. Further, in order to evaluate the humid heat resistance of the solar cell, the solar cell was maintained in an atmosphere at a temperature of 85 캜 and a relative humidity of 85% for 1000 hours. After 1000 hours, the transparent conductive film in the solar cell deteriorated and the conversion efficiency was remarkably deteriorated.

As described above, the use of the zinc oxide based transparent conductive film according to the present invention is advantageous in that it has a higher conversion efficiency than that of the conventional zinc oxide based transparent conductive film and has excellent chemical durability (heat and humidity resistance and heat resistance) It was found that the solar cell can be manufactured.

As described above, the characteristics of the solar cell according to the present invention are superior to those of the conventional solar cell. This is because the zinc oxide-based transparent conductive film of the present invention has excellent chemical durability (heat and humidity resistance and heat resistance) and also has high transmittance in the near-infrared region as well as in the visible region, I think it is because it was possible.

Industrial availability

The zinc oxide based transparent conductive film related to the present invention is excellent in permeability, low resistance, and chemical durability (resistance to humid heat and heat) even in the near infrared region (800 to 2500 nm). Therefore, when a transparent conductive oxide based zinc oxide film according to the present invention is used for a solar cell, for example, it is possible to utilize solar energy in the near infrared region, which has not been conventionally available, with high efficiency, Solar cells can be obtained.

1: Compound thin film solar cell
11: side metal electrode layer
12: light absorbing layer
13: Middle layer
14: Creation
15: oxide transparent electrode film
16: glass substrate

Claims (17)

A zinc oxide based transparent conductive film comprising a zinc atom, an oxygen atom, and M defined below,
The total number of zinc atoms, the number of oxygen atoms, the number of titanium atoms, the number of gallium atoms and the number of aluminum atoms is 99% or more with respect to the total number of atoms constituting the film,
The ratio ((number of titanium atoms + number of titanium atoms) of the total number of titanium atoms, the number of gallium atoms and the number of aluminum atoms to the total number of atoms of the zinc atoms, the titanium atoms, the gallium atoms, The number of gallium atoms + the number of aluminum atoms) / (the number of zinc atoms + the number of titanium atoms + the number of gallium atoms + the number of aluminum atoms) x 100) is not less than 1.3% and not more than 2.0%
Wherein the number of titanium atoms is at least 50% of the total number of atoms of the titanium atoms, the gallium atoms and the aluminum atoms contained in the film,
A carrier electron concentration of 3.60 x 10 ²⁰ cm ^-3 or less, a mobility of 43.0 cm 2 / Vs or more, and a specific resistance of 5.00 x 10 ^-4 Ω · cm or less.
M: a titanium atom, a titanium atom and a gallium atom, a titanium atom and an aluminum atom, or a titanium atom and a gallium atom and an aluminum atom The method according to claim 1,
The ratio of the total number of atoms of the titanium atom number, the gallium atom number, and the aluminum atom number ((the number of titanium atoms + the number of gallium atoms + the number of gallium atoms + the number of gallium atoms) (Number of atoms) / (number of zinc atoms + number of titanium atoms + number of gallium atoms + number of aluminum atoms) x 100) is 1.3% or more and 1.9% or less. 3. The method according to claim 1 or 2,
And a sheet resistance at a film thickness of 500 nm is 10? /? Or less. 1. A sintered body comprising a zinc atom, an oxygen atom, and M defined below,
Wherein the total of the number of zinc atoms, the number of oxygen atoms, the number of titanium atoms, the number of gallium atoms and the number of aluminum atoms is 99% or more with respect to the total number of atoms constituting the sintered body,
The ratio of the total number of titanium atoms, the number of gallium atoms and the number of aluminum atoms (((number of titanium atoms + number of gallium atoms) to the total number of atoms of the number of zinc atoms, the number of titanium atoms, (Number of atoms + number of aluminum atoms) / (number of zinc atoms + number of titanium atoms + number of gallium atoms + number of aluminum atoms) x 100) is not less than 1.3% and not more than 2.0%
Wherein the number of titanium atoms is at least 50% of the total number of titanium atoms, the number of gallium atoms and the number of aluminum atoms contained in the sintered body,
The relative density is 96.5% or more, b * in the L * a * b * color system is 0.00 or more, and L * is 46.00 or less.
M: a titanium atom, a titanium atom and a gallium atom, a titanium atom and an aluminum atom, or a titanium atom and a gallium atom and an aluminum atom 5. The method of claim 4,
The ratio ((number of titanium atoms + number of gallium atoms + number of gallium atoms + number of aluminum atoms) of the total number of titanium atoms, the number of gallium atoms and the number of aluminum atoms with respect to the total number of atoms of zinc atoms, (Number of zinc atoms + number of titanium atoms + number of gallium atoms + number of aluminum atoms) x 100) is 1.3% or more and 1.9% or less. 1. A method for producing a sintered body comprising a zinc atom, an oxygen atom, and M defined below,
A process for putting a raw material containing a zinc source and an M source into a mold, wherein the M source is represented by the following (i) to (iv)
(i) at least one titanium source selected from the group consisting of low valence titanium oxide, titanium black, titanium carbide and titanium nitride,
(ii) a mixture of the titanium source and at least one gallium source selected from the group consisting of gallium oxide and gallium nitride,
(iii) a mixture of the titanium source, at least one aluminum source selected from the group consisting of aluminum oxide, aluminum carbide and aluminum nitride,
(iv) mixing the titanium source, the gallium source, and the aluminum source,
Press-sintering a raw material in a mold at a temperature of 900 to 1200 DEG C and a pressure of 20 to 50 MPa in a vacuum or in an inert atmosphere for 2 to 5 hours,
Wherein the total of the number of zinc atoms, the number of oxygen atoms, the number of titanium atoms, the number of gallium atoms and the number of aluminum atoms is 99% or more with respect to the total number of atoms contained in the sintered body,
The ratio of the total number of titanium atoms, the number of gallium atoms and the number of aluminum atoms (((number of titanium atoms + number of gallium atoms) to the total number of atoms of the number of zinc atoms, the number of titanium atoms, (Number of atoms + number of aluminum atoms) / (number of zinc atoms + number of titanium atoms + number of gallium atoms + number of aluminum atoms) x 100) is not less than 1.3% and not more than 2.0%
Wherein the number of titanium atoms is at least 50% based on the total number of atoms of the titanium atom, the gallium atom and the aluminum atom contained in the sintered body.
M: a titanium atom, a titanium atom and a gallium atom, a titanium atom and an aluminum atom, or a titanium atom and a gallium atom and an aluminum atom 1. A method for producing a sintered body comprising a zinc atom, an oxygen atom, and M defined below,
A process for putting a raw material containing a zinc source and an M source into a die, wherein the M source is represented by the following (i) to (iv)
(i) at least one titanium source selected from the group consisting of low valence titanium oxide, titanium black, titanium carbide and titanium nitride,
(ii) a mixture of the titanium source and at least one gallium source selected from the group consisting of gallium oxide and gallium nitride,
(iii) a mixture of the titanium source, at least one aluminum source selected from the group consisting of aluminum oxide, aluminum carbide and aluminum nitride,
(iv) mixing the titanium source, the gallium source, and the aluminum source,
And a step of sintering the material in the die by discharge plasma at a temperature of 900 to 1200 캜 and a pressure of 20 to 50 MPa for 5 to 30 minutes,
Wherein the total of the number of zinc atoms, the number of oxygen atoms, the number of titanium atoms, the number of gallium atoms and the number of aluminum atoms is 99% or more with respect to the total number of atoms contained in the sintered body,
The ratio of the total number of titanium atoms, the number of gallium atoms and the number of aluminum atoms (((number of titanium atoms + number of gallium atoms) to the total number of atoms of the number of zinc atoms, the number of titanium atoms, (Number of atoms + number of aluminum atoms) / (number of zinc atoms + number of titanium atoms + number of gallium atoms + number of aluminum atoms) x 100) is not less than 1.3% and not more than 2.0%
Wherein the number of titanium atoms is at least 50% based on the total number of atoms of the titanium atom, the gallium atom and the aluminum atom contained in the sintered body.
M: a titanium atom, a titanium atom and a gallium atom, a titanium atom and an aluminum atom, or a titanium atom and a gallium atom and an aluminum atom 1. A method for producing a sintered body comprising a zinc atom, an oxygen atom, and M defined below,
A process for filling a raw material containing a zinc source and an M source into a metal capsule so that a filling rate of the raw material is 50% or more, wherein the M source is represented by (i) to (iv)
(i) at least one titanium source selected from the group consisting of low valence titanium oxide, titanium black, titanium carbide and titanium nitride,
(ii) a mixture of the titanium source and at least one gallium source selected from the group consisting of gallium oxide and gallium nitride,
(iii) a mixture of the titanium source, at least one aluminum source selected from the group consisting of aluminum oxide, aluminum carbide and aluminum nitride,
(iv) mixing the titanium source, the gallium source, and the aluminum source,
And a step of subjecting the capsule raw material to hot isostatic pressing at 900 to 1400 캜 for 1 to 4 hours while pressurizing the charged raw material in an inert gas atmosphere to 50 MPa or more,
Wherein the total of the number of zinc atoms, the number of oxygen atoms, the number of titanium atoms, the number of gallium atoms and the number of aluminum atoms is 99% or more with respect to the total number of atoms contained in the sintered body,
The ratio of the total number of titanium atoms, the number of gallium atoms and the number of aluminum atoms (((number of titanium atoms + number of gallium atoms) to the total number of atoms of the number of zinc atoms, the number of titanium atoms, (Number of atoms + number of aluminum atoms) / (number of zinc atoms + number of titanium atoms + number of gallium atoms + number of aluminum atoms) x 100) is not less than 1.3% and not more than 2.0%
Wherein the number of titanium atoms is at least 50% based on the total number of atoms of the titanium atom, the gallium atom and the aluminum atom contained in the sintered body.
M: a titanium atom, a titanium atom and a gallium atom, a titanium atom and an aluminum atom, or a titanium atom and a gallium atom and an aluminum atom 9. The method according to any one of claims 6 to 8,
The ratio ((number of titanium atoms + number of gallium atoms + number of gallium atoms) of the total atom number of titanium atoms, the number of gallium atoms and the number of aluminum atoms to the total number of atoms of zinc atoms, (Number of aluminum atoms) / (number of zinc atoms + number of titanium atoms + number of gallium atoms + number of aluminum atoms) x 100) is 1.3% or more and 1.9% or less. A method for forming a transparent conductive film of zinc oxide based on a substrate, which comprises the step of providing the sintered body according to claim 4 or 5 to a sputtering method, an ion plating method or an electron beam vapor deposition method to form a transparent conductive film of zinc oxide. A transparent conductive substrate comprising a transparent conductive material and a zinc oxide based transparent conductive film according to any one of claims 1 to 3. A light-absorbing layer made of a p-type semiconductor, an intermediate layer made of an n-type semiconductor, a window layer made of an n-type semiconductor, and a barrier layer made of any one of items 1 to 3 Wherein a transparent conductive film layer made of a zinc oxide-based transparent conductive film described in claim 1 is laminated in this order. A transparent electrode layer made of a transparent conductive oxide-zinc-based film according to any one of claims 1 to 3, a window layer made of an n-type semiconductor, an intermediate layer made of an n-type semiconductor, a light absorbing layer made of a p- , And a metal electrode are laminated in this order. The method according to claim 12 or 13,
Wherein the light absorption layer is made of at least one selected from CuInSe ₂ , CuInS ₂ , CuGaSe ₂ , CuGaS ₂ , solid solution thereof, and CdTe. The method according to claim 12 or 13,
The light absorbing layer, CuZnSe _2, CuZnS _2, CuSnSe _2, CuSnS and _2, a solar cell based compound at least composed as one selected from those of the solid solution. A silicon-based solar cell in which a first electrode layer, a light absorbing layer and a second electrode layer are laminated in this order, and a photovoltaic power is generated by light incident from the second electrode layer side,
Wherein at least the second electrode layer of the first electrode layer and the second electrode layer is composed of the zinc oxide-based transparent conductive film according to any one of claims 1 to 3. 17. The method of claim 16,
Wherein the light absorbing layer is made of at least one selected from an amorphous silicon type, a polycrystalline silicon type, and a microcrystalline silicon type.

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