JP2012184151A - Conductor substrate, method for manufacturing conductor substrate, device, electronic equipment, and solar cell panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductor substrate that can achieve resistance reduction at low cost, and has transparency even in an infrared region, a method of manufacturing the conductor substrate, a device, electronic equipment, and a solar cell panel.SOLUTION: The conductor substrate includes: a substrate; a seed layer that is provided on the substrate, consists of a material in which the a-axis length in a crystal structure corresponds to a tin oxide-based material, and controls a crystal growth; and a conductive layer that is provided on the seed layer, and consists of the crystal of a tin oxide-based transparent conductor.

Description

  The present invention relates to an electric substrate, a method for manufacturing a conductive substrate, a device, an electronic apparatus, and a solar cell panel.

  In recent years, there is a growing need for large-sized and small-sized liquid crystal display panels. In order to realize this, it is necessary to reduce the power consumption of the display element, and it is indispensable to apply a transparent electrode having a high visible light transmittance and a low resistance value. In particular, an organic electroluminescence element that is being developed recently is a self-luminous type and is effective in application to a small portable terminal, but has a problem that power consumption is large due to current driving. In addition, plasma display panels (PDPs) that are currently spreading on the market and field emission displays (FEDs) that are being developed as next-generation displays have a problem of high power consumption. From these points, there is a great expectation for reducing the resistance of the transparent conductive thin film.

  In recent years, solar cells are highly expected as a central technology in a decarbonized society. The solar cell has a configuration in which a transparent conductor is formed on a substrate. In a solar cell, the transparent conductor is an important factor that determines the conversion efficiency. In recent years, a technique using an infrared region among components of sunlight has been developed. For this reason, in the transparent conductor, transparency in the infrared region is strongly demanded. On the other hand, for example, as shown in Patent Document 1, Patent Document 2, Non-Patent Document 1, and Non-Patent Document 2, when a high mobility transparent conductor is used, high infrared transparency may be obtained. Are known.

International Publication No. 2008/146663 Pamphlet JP 2010-231972 A

T.A. Koida, H .; Fujiwara, and M.M. Kondo: Jpn. J. et al. Appl. Phys. 46 (2007) L685. T.A. Koida, H .; Fujiwara, and M.M. Kondo: Sol. Energy Mater. Sol. Cells 93 (2009) 851.

  However, conventionally, it is a transparent conductor using indium oxide, and it is highly movable to infrared by using a special element (hydrogen in the case of Patent Document 1, Non-Patent Document 1 and Non-Patent Document 2) as a dopant. Although a transparent transparent conductor has been produced, practical application is not easy at this stage. On the other hand, a transparent conductor using, for example, a tin oxide-based material that is widely used practically is demanded.

  Patent Document 2 describes the use of a solid solution of a substance having a rutile structure as a seed layer, but does not refer to the optimum composition of the seed layer, and also refers to infrared transparency. It has not been.

  In view of the circumstances as described above, an object of the present invention is to realize a low-cost and low-resistance electric substrate having transparency even in the infrared region, a method of manufacturing a conductive substrate, a device, and an electronic apparatus And providing a solar cell panel.

  The conductor substrate according to the present invention includes a substrate, a seed layer provided on the substrate, the a-axis length in the crystal structure being made of a material corresponding to the tin oxide material, and controlling the crystal growth, and the seed layer And a conductive layer made of a tin oxide-based transparent conductor crystal.

  According to the present invention, a substrate, a seed layer provided on the substrate, the a-axis length in the crystal structure being made of a material corresponding to the tin oxide material, and controlling the crystal growth, provided on the seed layer And the tin oxide transparent conductor crystal on the seed layer is formed in a state where the crystal orientation is controlled. . Thus, by optimizing the composition of the seed layer, it is possible to reduce the resistance of the tin oxide based transparent conductor. Moreover, since the crystal | crystallization of a tin oxide type transparent conductor becomes high mobility, high infrared transparency will be obtained. In addition, since the tin oxide transparent conductor crystal is grown on the seed layer, it is not necessary to use a single crystal substrate, and the cost can be reduced. Thereby, low resistance can be realized at low cost, and a conductive substrate having transparency even in the infrared region can be obtained.

The conductive substrate is characterized in that the substrate is an amorphous substrate.
According to the present invention, it is possible to reduce the cost by using an amorphous substrate as the substrate.

Said conductor board | substrate is a glass substrate, The said board | substrate is characterized by the above-mentioned.
According to the present invention, it is possible to reduce the cost by using a glass substrate as the substrate. In addition, it can be widely applied to products used by forming a conductor on a glass substrate.

In the conductive substrate, the seed layer includes a substance having a rutile structure as a crystal structure.
According to the present invention, since the seed layer includes a substance having a rutile structure as a crystal structure, the crystallinity of the crystal of the tin oxide based transparent conductor formed on the seed layer can be improved. Thereby, a low-resistance conductor can be obtained.

The conductive substrate is characterized in that the substance is at least one of TiO ₂ , NbO ₂ , MgF ₂ and SnO ₂ .
According to the present invention, in order to optimize the composition of the seed layer, at least one of TiO ₂ , NbO ₂ , MgF _2, and SnO ₂ is used as the material having a rutile structure. The body can be easily obtained.

The conductor substrate is characterized in that the tin oxide based transparent conductor crystal has a (001) orientation.
According to the present invention, since the crystal of the tin oxide transparent conductor has the (001) orientation, a high mobility tin oxide transparent conductor crystal can be obtained.

A method of manufacturing a conductor substrate according to the present invention includes a seed layer forming step of forming a seed layer for controlling crystal growth on a substrate using a substance having an a-axis length corresponding to a tin oxide-based material in a crystal structure; And a crystal growth step of growing a tin oxide transparent conductor crystal on the seed layer.
According to the present invention, a seed layer for controlling crystal growth is formed on a substrate using a substance whose a-axis length in the crystal structure corresponds to a tin oxide-based material, and the tin oxide-based transparent conductor is formed on the seed layer. Therefore, it is possible to form a tin oxide transparent conductor layer having high crystallinity while controlling the crystal growth by the seed layer. In addition, by optimizing the composition of the seed layer, the tin oxide transparent conductor crystal is formed so as to have high mobility, so that high infrared transparency can be obtained. In addition, since the tin oxide transparent conductor crystal is grown on the seed layer, it is not necessary to use a single crystal substrate, and the cost can be reduced. Thereby, a low-resistance conductor substrate having transparency even in the infrared region can be manufactured at low cost.

In the method for manufacturing a conductor substrate, the seed layer forming step forms the seed layer using a pulse laser deposition method.
According to the present invention, since the seed layer is formed using the pulse laser deposition method, the seed layer can be easily formed.

The above method for manufacturing a conductive substrate is characterized in that an amorphous substrate is used as the substrate.
According to the present invention, since the amorphous substrate is used as the substrate, the conductor substrate can be manufactured at a low cost.

The method for manufacturing a conductor substrate described above is characterized in that a glass substrate is used as the substrate.
According to the present invention, since the glass substrate is used as the substrate, the conductor substrate can be manufactured at low cost.

In the method for manufacturing a conductor substrate, the seed layer forming step forms a layer containing a substance having a rutile structure as the seed layer.
According to the present invention, in the seed layer forming step, a layer containing a substance having a rutile structure as a seed layer is formed as the seed layer. Therefore, the crystal of the tin oxide based transparent conductor formed on the seed layer is formed. Crystallinity can be improved. Thereby, a low-resistance conductor can be obtained.

The method for manufacturing a conductive substrate is characterized in that at least one of TiO ₂ , NbO ₂ , MgF ₂ and SnO ₂ is used as the substance.
According to the present invention, in order to optimize the composition of the seed layer, at least one of TiO ₂ , NbO ₂ , MgF _2, and SnO ₂ is used as the material having a rutile structure. Can get to.

The above-described method for manufacturing a conductive substrate is characterized in that the crystal of the tin oxide-based transparent conductor has a (001) orientation.
According to the present invention, since the crystal of the tin oxide transparent conductor has the (001) orientation, a high mobility tin oxide transparent conductor crystal can be obtained.

A device according to the present invention includes the above-described conductor substrate.
According to the present invention, a low resistance can be realized at low cost, and since a conductive substrate having transparency in the infrared region is provided, a device having high electrical characteristics can be obtained at low cost. .

An electronic apparatus according to the present invention includes the above device.
According to the present invention, since a device having high electrical characteristics and low cost is provided, a high-quality electronic device can be provided at low cost.

A solar cell panel according to the present invention includes the above-described conductor substrate.
According to the present invention, low resistance can be realized at low cost, and since a conductive substrate having transparency in the infrared region is provided, a solar cell panel with high conversion efficiency can be obtained at low cost.

  According to the present invention, it is possible to provide an electric substrate, a method of manufacturing a conductive substrate, a device, an electronic apparatus, and a solar cell panel that can realize low resistance at low cost and have transparency even in the infrared region. It is in.

Schematic which shows the conductor board | substrate which concerns on embodiment of this invention. The figure which shows the length of the a-axis in a crystal structure, and the length of a c-axis. The schematic diagram which shows the structure of a pulse laser apparatus. The figure which shows the result which concerns on the Example of this invention. The figure which shows the result which concerns on the Example of this invention. The figure which shows the result which concerns on the Example of this invention. The figure which shows the result which concerns on the Example of this invention. The figure which shows the result which concerns on the Example of this invention. The figure which shows the result which concerns on the Example of this invention.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a cross-sectional view showing the configuration of the conductor substrate 1.
As shown in the figure, the conductor substrate 1 has a substrate 11, a seed layer 12 and a conductive layer 13.

  The substrate 11 is a substrate made of an amorphous material such as glass. In addition to this, the substrate 11 may be, for example, a single crystal material, a polycrystalline material, an amorphous material, or a material in which these crystal states are mixed. It may be a plastic material. Specific examples include a substrate made of strontium titanate (SrTiO3) single crystal or polycrystal, a single crystal substrate or polycrystal substrate made of a rock salt type crystal having a perovskite type crystal structure or a similar structure, a quartz substrate, and a non-alkali glass. Examples thereof include a glass substrate such as Asahi Glass Co., Ltd. (product name: AN100), a semiconductor substrate such as a plastic substrate, and a silicon substrate (thermally oxidized Si substrate) on which a thermal oxide film is formed. These may contain dopants, impurities and the like as long as the effects of the present invention are not impaired. The shape of the substrate 11 in the present invention is not particularly limited. For example, it may be a plate-like substrate 11 or a film.

  The thickness of the substrate 11 is not particularly limited. When the transparency of the substrate 11 is required, for example, 1 mm or less is preferable. If a plate-like substrate is required to have mechanical strength and the transmittance may be sacrificed somewhat, it may be thicker than 1 mm. The thickness of the substrate 11 is preferably 0.2 to 1 mm, for example.

  The substrate 11 can be polished if necessary. A substrate having crystallinity such as a SrTiO 3 substrate is preferably used after being polished. For example, mechanical polishing is performed using diamond slurry as an abrasive. In the mechanical polishing, it is preferable to gradually refine the particle size of the diamond slurry to be used, and finally perform mirror polishing with a diamond slurry having a particle size of about 0.5 μm. Then, it may be further flattened by polishing using colloidal silica until the root mean square roughness (rms) of the surface roughness is 10 Å (1 nm) or less.

  Prior to the formation of the seed layer 12, the substrate 11 may be pretreated. The preprocessing can be performed by the following procedure, for example. First, the substrate is washed with acetone, ethanol or the like. Next, the substrate is immersed in high-purity hydrochloric acid (for example, EL grade, concentration 36 mass%, manufactured by Kanto Chemical Co., Inc.) for 2 minutes. Next, the substrate is moved into pure water and rinsed with hydrochloric acid or the like. Next, the substrate is moved into new pure water, and ultrasonic cleaning is performed for 5 minutes. Next, the substrate is taken out from the pure water, and nitrogen gas is blown onto the substrate surface to remove moisture from the substrate surface. These treatments are performed at room temperature, for example. These treatments are considered to remove oxides, organic substances, etc. from the substrate surface. Although hydrochloric acid was used in the above example, an acid such as aqua regia or hydrofluoric acid may be used instead. Further, the treatment with an acid may be performed at room temperature, or a heated acid may be used.

The seed layer 12 is provided on the substrate 11 and is a layer that controls crystal growth. The seed layer 12 is formed using a substance having an a-axis length in the crystal structure corresponding to a tin oxide-based material. An example of such a substance is a substance whose crystal structure is a rutile structure. When the seed layer 12 contains a substance having a rutile structure as a crystal structure, the crystallinity of the crystal of the conductive layer 13 formed on the seed layer 12 is improved. As such a substance, for example, at least one of TiO ₂ , NbO ₂ , MgF _2, and SnO ₂ is preferably used. In addition to these substances, as shown in the graph of FIG. 2, the material in which the a-axis length in the crystal structure corresponds to the tin oxide-based material, that is, the a-axis length coincides with, for example, tin oxide. A material that approximates within a range of 4 to 5.0 angstroms may be used. The approximate range can be a range in which the orientation of the conductive layer 13 formed on the seed layer 12 is in the (001) axis direction. 2 is the length of the a-axis in the crystal structure, and the horizontal axis of the graph is the length of the c-axis in the crystal structure.

  The conductive layer 13 is a transparent conductive layer made of, for example, a tin oxide based conductor. In the present embodiment, the conductive layer 13 is not directly formed on the substrate 11 but is formed on the seed layer 12. For example, when the seed layer 12 is a layer in which the crystal structure includes a rutile structure, the crystal structure of the conductive layer 13 is a crystal structure grown in the (001) axis direction. For this reason, it becomes the low resistance conductive layer 13 excellent in conductivity. For example, in the case where a layer containing a substance whose crystal structure is a rutile structure is formed as the seed layer 12, the conductive layer 13 is a layer having high crystallinity. For this reason, it becomes the low-resistance conductive layer 13 that is also excellent in conductivity.

Next, a method for manufacturing the conductor substrate 1 configured as described above will be described.
In the conductive substrate 1, a seed layer forming step for forming a seed layer 12 for controlling crystal growth on the substrate 11, and a tin oxide transparent conductive crystal is grown on the seed layer 12 to form a conductive layer 13. It is manufactured through a crystal growth step.

  In the seed layer forming step, the seed layer 12 may be formed using a physical vapor deposition (PVD) method such as a pulsed laser deposition (PLD) method or a sputtering method, for example, an MOCVD method or the like. You may form the seed layer 12 using the film-forming method by the synthesis process from solutions, such as a chemical vapor deposition (CVD) method, a sol gel method, and a chemical solution method. In particular, the PLD method is preferable because a good film state can be easily obtained, and the sputtering method is preferable because a film can be easily formed regardless of the crystallinity of the substrate.

  FIG. 3 is a schematic configuration diagram illustrating an example of a PLD apparatus 30 that is preferably used in the present method. The PLD apparatus 30 is arranged in a chamber 31 such that the substrate 11 and the target 39 face each other and the facing surfaces are substantially parallel to each other. The chamber 31 is capable of producing a high-quality thin film by maintaining an appropriate degree of vacuum and preventing impurities from entering from the outside.

  The substrate 11 can be rotated around a rotation axis 35 perpendicular to the surface of the substrate 11 by a motor (not shown). The target 39 is also rotatable about a rotation axis 38 perpendicular to the surface 39a by a motor (not shown).

  An infrared lamp 36 for heating the substrate 11 is installed in the chamber 31. The temperature of the substrate 11 is monitored by a radiation thermometer 37 installed outside the chamber 31 through the window 31b, and is controlled to always be a constant temperature.

A gas supply unit 44 is provided outside the chamber 31, and oxygen gas can be injected into the chamber 31 through an oxygen gas flow rate adjustment valve 45 for adjusting the flow rate of oxygen gas. Further, a turbo molecular pump 42 and a pressure valve 43 are connected to the chamber 31 in order to realize film formation under reduced pressure. The pressure in the chamber 31, oxygen gas with a flow rate adjusting valve 45 and the pressure valve 43, for example, the oxygen partial pressure is ^{1 × 10 -5 ~1 × 10 -4} Torr (1.33 × 10 -3 Pa~1. 33 × 10 ⁻² Pa). The turbo molecular pump 42 is connected to an oil rotary pump 40 and a backflow prevention valve 41, and the pressure on the exhaust side of the turbo molecular pump 42 is always 10 ⁻³ torr (1.33 × 10 ⁻¹ Pa) or less. To be kept.

  An optical oscillator 32 is provided outside the chamber 31, and a pulse laser beam oscillated by the optical oscillator 32 reflects a reflector 33 for adjusting the irradiation position, a lens 34 for controlling a spot diameter, and the chamber 31. The light is incident on the surface 39a of the target 39 facing the substrate 11 through the window 31a. The optical oscillator 32 oscillates a KrF excimer laser having a pulse frequency of 1 to 10 Hz, a laser fluence (laser power) of 1 to 2 J / cm 2 and a wavelength of 248 nm, for example, as pulse laser light.

  The oscillated pulsed laser light is spot-adjusted by the reflecting mirror 33 and the lens 34 so that the focal position is in the vicinity of the target 39 and is incident on the surface 39a of the target 39 at an angle of about 45 °. The target 39 is made of, for example, an Nb: TiO 2 sintered body containing 6 atomic% of Nb. Nb: TiO2 is an example in which the dopant (M) is Nb. The dopant (M) may be any of the dopants in the present invention mentioned above, and a plurality of types of metals may be used in combination.

For example, the Nb: TiO ₂ sintered body is prepared by mixing TiO ₂ and Nb ₂ O ₅ powders that are weighed so as to have a desired atomic ratio (eg, Nb: Ti = 0.45: 0.55). It can be produced by thermoforming the mixed powder. The composition of the target is almost the same as the composition of the film.

In order to form the seed layer 12 using the PLD apparatus 30, first, the substrate 11 is placed in the chamber 31. Next, in order to remove impurities on the substrate surface and to obtain a flat surface at the atomic level, pretreatment annealing is performed under conditions of an oxygen partial pressure of 10 ⁻⁵ Torr (1.33 × 10 ⁻³ Pa) and a substrate temperature of 500 ° C. You may go. The pretreatment annealing is preferably performed for 1 hour or more, for example.

Next, the substrate temperature is set to a predetermined value while maintaining the oxygen partial pressure in the chamber at about 1 × 10 ⁻⁵ to 1 × 10 ⁻⁴ Torr (1.33 × 10 ⁻³ Pa to 1.33 × 10 ⁻² Pa). And the substrate 11 is driven to rotate. Further, by intermittently irradiating the pulsed laser light while rotating the target 39, the temperature of the surface of the target 39 is rapidly increased to generate ablation plasma. Ti atoms, Nb atoms, and O atoms contained in the ablation plasma move to the substrate 11 while gradually changing the state while repeating a collision reaction with the oxygen gas in the chamber 31. Then, the particles containing Ti atoms, Nb atoms, and O atoms that have reached the substrate 11 are diffused as they are on the surface of the substrate 11 to be thinned. Thus, the seed layer 12 is formed on the substrate 11.

In the present embodiment, the metal oxide layer 12 as a conductor is formed through a step of annealing the seed layer 12 in a reducing atmosphere (hereinafter sometimes referred to as post-annealing). The reducing atmosphere in the present invention means that the partial pressure of the oxidizing gas in the atmosphere is 0.2 × 10 ⁵ Pa or less. The oxidizing gas means a gas that can give oxygen to the seed layer 12 in the annealing step, and specific examples include O ₂ , O ₃ , NO, NO ₂ , H ₂ O, and the like. When two or more kinds of oxidizing gases are contained in the atmosphere, the sum of their partial pressures may be within the range. The partial pressure of the oxidizing gas in the reducing atmosphere is preferably 1 × 10 ⁴ Pa or less, and more preferably 10 Pa or less. About 1 × 10 ⁻⁸ Pa is most preferable. The smaller the value of the partial pressure of the oxidizing gas, the lower the resistance of the metal oxide layer 12 can be obtained. In order to further reduce the resistance of the metal oxide layer 12, it is preferable that H ₂ and / or CO exist in the reducing atmosphere, and it is more preferable that H 2 in a plasma state exist.

  The annealing in the present invention refers to an operation of raising the seed layer 12 to a predetermined temperature (annealing temperature) and then lowering the temperature. When the seed layer 12 is formed on the substrate 11 as in this embodiment, the substrate temperature can be applied as the annealing temperature. The annealing temperature is preferably higher than the crystallization temperature of the seed layer 12. For example, the crystallization temperature of TiO 2 to which no dopant is added is about 400 ° C., and when the dopant is added, the crystallization temperature tends to decrease. Therefore, a preferable annealing temperature for satisfactorily reducing the resistance of the metal oxide layer 12 depends on the kind of the dopant, but is preferably 300 ° C. or higher. In view of heat resistance of the substrate 11, energy reduction, shortening of temperature raising time, etc., a lower annealing temperature is desirable. A more preferable range of the annealing temperature is 350 to 850 ° C., and 350 to 800 ° C. is more preferable.

  The time for maintaining the predetermined annealing temperature (annealing time) is not particularly limited. What is necessary is just to obtain a desired characteristic after annealing, for example, it can set within the range of 1-120 minutes. Although depending on other conditions, the annealing time is preferably 1 to 60 minutes, for example.

After the seed layer 12 is thus formed on the substrate 11, a crystal growth step is performed. In the crystal growth step, the conductive layer 13 is formed by growing a crystal of a tin oxide based transparent conductor on the seed layer 12. In the present embodiment, SnO ₂ doped with, for example, tungsten (W) or tantalum (Ta) is used as the tin oxide-based transparent conductor. As a method for forming the conductive layer 13, as in the method for forming the seed layer 12, for example, a physical vapor deposition (PVD) method such as a pulse laser deposition method or a sputtering method, or a chemical vapor deposition (CVD method such as an MOCVD method). ) Method, a sol-gel method, a chemical solution method, or the like. In this embodiment, since the conductive layer 13 is grown on the seed layer 12 containing a substance having a rutile structure as the crystal structure, the crystal of the conductive layer 13 grows in the (001) axis direction.

  As described above, according to the present embodiment, the seed layer 12 for controlling crystal growth is formed on the substrate 11 using a substance having an a-axis length corresponding to the tin oxide-based material in the crystal structure. Since the crystal of the conductive layer 13 made of a tin oxide-based transparent conductor is grown thereon, the conductive layer 13 of the tin oxide-based transparent conductor having high crystallinity is formed while the crystal growth is controlled by the seed layer 12. be able to. Moreover, since the crystal | crystallization of a tin oxide type transparent conductor becomes high mobility, high infrared transparency will be obtained. In addition, since the tin oxide transparent conductor crystal is grown on the seed layer 12, it is not necessary to use a single crystal substrate, and the cost can be reduced. Thereby, low resistance can be realized at low cost, and the conductive substrate 1 having transparency even in the infrared region can be manufactured.

  In addition, according to the present embodiment, the seed layer 12 for controlling crystal growth is formed on the substrate 11 using a substance whose a-axis length in the crystal structure corresponds to the tin oxide-based material. Since the crystal of the tin oxide-based transparent conductive layer 13 is grown, the tin oxide-based conductive layer 13 having high crystallinity can be formed while the crystal growth is controlled by the seed layer 12. In addition, since the crystal of the conductive layer 13 is formed so as to have high mobility, high infrared transparency can be obtained. In addition, since the conductive layer 13 is grown on the seed layer 12, it is not necessary to use a single crystal substrate, and the cost can be reduced. Thereby, a low-resistance conductor substrate having transparency even in the infrared region can be manufactured at low cost.

The technical scope of the present invention is not limited to the embodiments, and can be appropriately modified without departing from the spirit of the present invention.
The conductor substrate 1 of the present invention has a wide range of applications, such as the production of an intermediate layer for forming a copper oxide-based high-temperature superconductor thin film on a tape substrate, a light emitting diode, a semiconductor laser, etc. on an amorphous substrate. It can be used for forming a thin film device. It can also be used as a transparent circuit on an amorphous substrate using a transparent conductor thin film.

  For example, further cost reduction can be expected by forming a thin film on a glass or plastic substrate. For example, when it is used for a copper oxide-based high-temperature superconductor wire or the like, it can be said that the benefits obtained by cost reduction are great. In addition to cost reduction, a highly functional thin film device on a glass or plastic substrate can be formed. For example, a zinc oxide light emitting diode can be formed, and a flexible device can be realized.

Besides, for example, application to a transparent electrode such as a flat panel display, a solar cell, and a touch panel is conceivable. Further, it can be applied to the shielding of electromagnetic waves used for the antireflection film, a film that prevents dust from sticking due to static electricity, an antistatic film, heat ray reflective glass, and ultraviolet reflective glass. If a multilayer film composed of a layer made of SiO ₂ and a TiO ₂ layer doped with Nb is produced, it can also be applied as an antireflection film.

  Examples of applications include dye-sensitized solar cell electrodes; display panels, organic EL panels, light-emitting elements, light-emitting diodes (LEDs), white LEDs and laser transparent electrodes; surface-emitting laser transparent electrodes; lighting devices; An application that allows light to pass through only a specific wavelength range is also conceivable.

  Further specific applications can include the following. Transparent conductive film in a liquid crystal display (LCD); Transparent conductive film in a color filter part; Transparent conductive film in an EL (Electro Luminescence) display; Transparent conductive film in a plasma display (PDP); PDP optical filter Transparent conductive film for shielding electromagnetic waves; transparent conductive film for shielding near infrared; transparent conductive film for preventing surface reflection; transparent conductive film for improving color reproducibility; transparent conductive film for preventing damage Optical filter; touch panel; resistive touch panel; electromagnetic induction touch panel; ultrasonic touch panel; optical touch panel; capacitive touch panel; resistive touch panel for personal digital assistants; Panel]; solar cell; amorphous silicon (a-Si) solar cell; microcrystalline Si thin film solar cell; CIGS solar cell; dye-sensitized solar cell (DSC); transparent conductive material for static electricity countermeasures for electronic parts; Transparent conductive material; dimming material; dimming mirror; heating element (surface heater, electrothermal glass); electromagnetic wave shielding glass.

Next, examples of the present invention will be described.
In this example, a glass substrate (Corning 1737 non-alkali glass) was used as the substrate 11. The seed layer _12, to prepare a _{Ti 1-x Nb x O y} + 2 ( film thickness 10 nm). As the conductive layer 13, SnO ₂ doped with W was prepared. The conductive layer 13 was formed at room temperature using the PLD method. The film forming temperature was 600 ° C., and the oxygen partial pressure was 5 mTorr. The laser conditions were 20 mJ, 2 Hz, and 1 h.

FIG. 4 is a graph showing changes in lattice constant in Ti _1-x Nb _x O _{y + 2} . The horizontal axis of the graph indicates the value of x, and the vertical axis of the graph indicates the c-axis length, the a-axis length, and (c-axis length) / (a-axis length). As can be seen from FIG. 4, the a-axis length can be made to correspond by using the composition of Ti _0.4 Nb _0.6 O ₂ .

FIG. 5 is a graph showing an XRD measurement result of the formed Ti _1-x Nb _x O _{y + 2} seed layer 12. The horizontal axis of the graph is a value of 2θ, and the vertical axis of the graph is a relative value indicating the size of the peak. FIG. 5 shows that the Ti _1-x Nb _x O _{y + 2} seed layer 12 shows the largest orientation in the (002) axis direction when x = 0.45. FIG. 6 is a photograph showing an XRD pattern of a Ti _1-x Nb _x O _{y + 2} seed layer. From the photograph in FIG. 6, a strong orientation is recognized in the (002) axis.

FIG. 7 is a graph showing the mobility of the conductive layer 13 formed on the Ti _1-x Nb _x O _{y + 2} seed layer 12. The horizontal axis of the graph is the value of x, and the vertical axis of the graph is the mobility. As shown in FIG. 7, the maximum value of mobility was 136 cm ² V ⁻¹ s ^{−1 at} x = 0.45. The carrier density at this time was 1.4 × 10 ²⁰ cm ⁻³ .

FIG. 8 is a graph showing the relationship between carrier density and mobility in the conductive layer 13 formed on the Ti _1-x Nb _x O _{y + 2} seed layer 12. The horizontal axis of the graph is the carrier density, and the vertical axis of the graph is the mobility. FIG. 8 shows two results (1) and (2). Of the two results, result (1) is the value for this example. Further, the result (2) is a result when SnO ₂ doped with Ta is used as the conductive layer 13 and an anatase Ti _1-x Nb _x O _{y + 2} seed layer is used as the seed layer 12.

  In the result (1) in this example, the carrier density is lower and the mobility is higher than the result (2). For this reason, when the conductive layer 13 is used as an electrode of a solar cell, excellent electrical characteristics and infrared light transmittance can be obtained.

  FIG. 9 is a graph showing optical characteristics of the conductive layer 13 obtained in this example. The horizontal axis of the graph indicates the wavelength of light, the vertical axis on the left side of the graph indicates the light transmittance of the conductive layer 13, and the vertical axis on the right side of the graph indicates the light absorption rate of the conductive layer 13. Is shown. Moreover, the graph (1) of FIG. 9 has shown the light transmittance, and the graph (2) has shown the light absorption rate.

  As can be seen from FIG. 9, the light absorptance is as low as 3.5% for light having a wavelength of 1400 nm. Further, the light transmittance is as high as 70% or higher until the wavelength exceeds 2450 nm. For this reason, when the conductive layer 13 is used as an electrode of a solar cell, excellent infrared light transmittance can be obtained.

DESCRIPTION OF SYMBOLS 1 ... Conductive substrate 11 ... Substrate 12 ... Seed layer 13 ... Conductive layer

Claims (16)

A substrate,
A seed layer provided on the substrate, the a-axis length in the crystal structure is made of a substance corresponding to the tin oxide-based material, and controls crystal growth;
A conductive substrate comprising: a conductive layer provided on the seed layer and made of a crystal of a tin oxide based transparent conductive material. The conductor substrate according to claim 1, wherein the substrate is an amorphous substrate. The conductor substrate according to claim 1, wherein the substrate is a glass substrate. The conductor substrate according to any one of claims 1 to 3, wherein the seed layer includes a substance having a rutile structure as a crystal structure. The conductor substrate according to claim 4, wherein the substance is at least one of TiO ₂ , NbO ₂ , MgF _2, and SnO ₂ . The conductor substrate according to any one of claims 1 to 5, wherein the crystal of the tin oxide-based transparent conductor has a (001) orientation. A seed layer forming step of forming a seed layer for controlling crystal growth on a substrate using a substance having an a-axis length corresponding to a tin oxide-based material in the crystal structure;
And a crystal growth step of growing a tin oxide based transparent conductor crystal on the seed layer. The said seed layer formation step forms the said seed layer using a pulse laser deposition method. The manufacturing method of the conductor substrate of Claim 7 characterized by the above-mentioned. The method for manufacturing a conductor substrate according to claim 7 or 8, wherein an amorphous substrate is used as the substrate. A glass substrate is used as the substrate. The method of manufacturing a conductor substrate according to any one of claims 7 to 9, wherein the substrate is a glass substrate. The said seed layer formation step forms the layer containing the substance whose crystal structure is a rutile structure as said seed layer. The conductor substrate as described in any one of Claims 7-10 characterized by the above-mentioned. Production method. The method for manufacturing a conductor substrate according to claim 11, wherein at least one of TiO ₂ , NbO ₂ , MgF _2, and SnO ₂ is used as the substance. The method for producing a conductor substrate according to any one of claims 7 to 12, wherein the tin oxide transparent conductor crystal has a (001) orientation.   A device comprising the conductor substrate according to any one of claims 1 to 6.   An electronic apparatus comprising the device according to claim 14.   A solar cell panel comprising the conductor substrate according to any one of claims 1 to 6.