JP2003142712A - Solar battery and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a solar battery capable of manufacturing an (i) type fine crystal silicon layer or poly-crystal silicon layer having a (110) high orientation rate in a much lower temperature at low costs. SOLUTION: A first transparent electrode, a fine crystal Si layer or poly- crystal Si layer having pin structure or nip structure, a second transparent electrode, and a back electrode are successively formed on a transparent insulating substrate, so that a solar battery for making a light incident from the transparent insulating substrate side can be manufactured. In this case, at least the (i) type fine crystal Si layer or poly-crystal Si layer are heated by making the supporting electrode of a CVD device support an object to be treated having the transparent insulating substrate, and the mixed gas of chlorinated silicon group compound gas and H2 is supplied as raw material gas from a gas supply means to a reaction container, and a power for generating glow discharge whose frequency is 60 MHz or more is supplied from a power source to a ladder-type electrode so that glow discharge can be generated in the reaction container, and that plasma can be generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a solar cell and a solar cell, and more particularly to an i-type microcrystalline silicon layer or a polycrystalline silicon layer of a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure. And a solar cell.

[0002]

2. Description of the Related Art In a solar cell having a thin film crystalline silicon layer (microcrystalline Si layer or polycrystalline Si layer) having a pin structure, an i-type microcrystalline Si layer or polycrystalline S layer which is a power generation layer is used.
It is known that improving the quality of the i layer (mainly (110) preferred orientation, low defect density, etc.) is useful for improving the photoelectric conversion efficiency. The (110) preferential orientation is generally judged by comparing the diffraction intensity from the (220) plane with the diffraction intensity from the other plane in the X-ray diffraction pattern. Here, in the thin film silicon crystal formed by plasma CVD The ratio of the diffraction intensity between the (220) plane and the (111) plane, which is the main peak, is defined as the (110) orientation ratio.

By the way, in the Institute of Electronics Technology, Vol. 63, No. 1 and No. 2, an i-type microcrystalline Si layer (i layer) is referred to as Si.
By introducing H ₄ gas as a source gas into the chamber of the plasma CVD apparatus to generate plasma in the chamber, the ambient temperature (temperature of the substrate to be processed to be formed) is set to 3
By forming the film at a high temperature exceeding 50 ° C., the i
It is disclosed that the layer exhibits a prominent (110) preferred orientation. However, for example, in the production of a solar cell of the type in which light is incident from the surface of a transparent insulating substrate and has thin film crystalline silicon (microcrystalline Si or polycrystalline Si) having a pin structure, the i layer is manufactured at a high temperature exceeding 300 ° C. When you make a film,
The following problems occur.

That is, the solar cell having the simplest structure has a first transparent electrode 102, a p-type microcrystalline Si layer (p layer) 103, and an i-type microcrystalline Si on a transparent insulating substrate 101 as shown in FIG. Layer (i layer) 104, n-type microcrystalline Si layer (n layer)
It is manufactured by sequentially forming 105, the second transparent electrode 106, and the back electrode 107. Generally, a metal oxide such as tin oxide is used for the first and second transparent electrodes 102 and 106, but when the i layer 104 is formed, a raw material gas such as H ₂ or SiH ₄ gas is used. Hydrogen radicals derived from are generated in plasma. This hydrogen radical diffuses in the p-layer 103 as shown in FIG. 13, and when it reaches the first transparent electrode 102 on the lower side, the reduction reaction causes the extraction of oxygen of the metal oxide as the electrode material. The reduction reaction is remarkably promoted when the i layer 104 is formed at a high temperature, so that the transparency of the first transparent electrode 102 is lowered, the light transmittance is lowered, and the photoelectric conversion efficiency is lowered. .

By heating the transparent insulating substrate 101 to a high temperature, diffusion of p-type impurities (for example, boron) from the p layer 103 to the i layer 104 is promoted as shown in FIG. P-type diffusion layer 1 on the i layer 104 side of
Since 08 is formed, the electrical characteristics of the junction interface are deteriorated, the leakage current is increased, and the photoelectric conversion efficiency is reduced.

Therefore, when the substrate temperature is increased to form the i-type microcrystalline Si layer 104 having the (110) preferential orientation as in the conventional case, the optical characteristics of the transparent electrode 102 deteriorate and the pi junction interface is formed. The electric characteristics are deteriorated due to the formation of the p-type diffusion layer 108, and there is a problem that the photoelectric conversion efficiency is lowered.

Further, a back surface electrode, a first electrode, is formed on the transparent insulating substrate.
Transparent electrode, n-type microcrystalline Si layer (n layer), i-type microcrystalline S
In a solar cell having a structure in which an i layer (i layer), a p-type microcrystalline Si layer (p layer), and a second transparent electrode are sequentially formed, and the light is incident from the second transparent electrode side, the i layer is described above. As described above, when the film is formed at a temperature higher than 300 ° C., the light transmissivity of the first transparent electrode is lowered, and the photoelectric conversion efficiency is lowered due to the formation of the n-type impurity layer on the i layer side of the ni junction interface.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, a second transparent electrode and a back electrode are sequentially formed on a transparent insulating substrate. In manufacturing a solar cell having a structure in which light is incident from the transparent insulating substrate side, at least an i-type microcrystalline silicon layer or a polycrystalline silicon layer is manufactured at a lower temperature and at a lower cost as compared with the conventional technology. By forming the film, the i-type microcrystalline silicon layer or the polycrystalline silicon layer is formed (110) without deteriorating the light transmittance of the first transparent electrode and deteriorating the electrical characteristics at the pi junction interface or the ni junction interface. ) It is intended to provide a method for manufacturing a solar cell capable of preferential orientation.

According to the present invention, a back electrode is provided on a transparent insulating substrate,
In manufacturing a solar cell having a structure in which a first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, and a second transparent electrode are sequentially formed, and light is incident from the second transparent electrode side, By forming at least an i-type microcrystalline silicon layer or a polycrystalline silicon layer at a lower temperature and at a lower cost as compared with the prior art, a decrease in light transmittance of the first transparent electrode, a pi junction interface or a ni junction is formed. An object of the present invention is to provide a method for manufacturing a solar cell capable of (110) preferentially orienting the i-type microcrystalline silicon layer or the polycrystalline silicon layer without deteriorating the electrical characteristics at the interface. .

The present invention provides a (110) preferred orientation i
P containing a microcrystalline silicon layer or a polycrystalline silicon layer
It is intended to provide a solar cell having an in-structure microcrystalline silicon layer or a polycrystalline silicon layer.

[0011]

A method of manufacturing a solar cell according to the present invention comprises a first transparent electrode on a transparent insulating substrate and a pi
In manufacturing a solar cell in which a microcrystalline silicon layer or a polycrystalline silicon layer having an n structure or a nip structure, a second transparent electrode, and a back electrode are sequentially formed, and light is incident from the transparent insulating substrate side, A reaction vessel, a gas supply means for supplying a raw material gas to the reaction vessel, a discharge means for discharging a gas in the reaction vessel, a discharge ladder electrode arranged in the reaction vessel, and A power source for supplying glow discharge generation power to the discharge ladder electrode, and a support electrode that is arranged in the reaction vessel in parallel with the discharge ladder electrode and is spaced apart from the discharge ladder electrode, and includes a heater for heating. Using a CVD apparatus, the pin structure or n
Of the microcrystalline silicon layer or the polycrystalline silicon layer having the ip structure, at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer supports an object to be processed having the transparent insulating substrate as a support electrode of the CVD device. Let it heat, S
A mixed gas of at least one silicon chlorinated compound gas selected from iH ₄ and SiH ₂ Cl ₂ , SiHCl ₃ and SiCl ₄ and H ₂ is supplied as the raw material gas from the gas supply means into the reaction vessel, A film is formed by supplying a glow discharge generation power having a frequency of 60 MHz or more from the power supply to the ladder electrode to cause glow discharge in the reaction vessel to generate plasma.

Another method for manufacturing a solar cell according to the present invention is
A back electrode, a first transparent electrode, and a pi on a transparent insulating substrate.
In manufacturing a solar cell in which a microcrystalline silicon layer or a polycrystalline silicon layer having an n structure or a nip structure and a second transparent electrode are sequentially formed and light is incident from the second transparent electrode side, a reaction container and a Gas supply means for supplying a raw material gas to the reaction vessel, discharge means for discharging the gas in the reaction vessel, a discharge ladder type electrode arranged in the reaction vessel, and a ladder type for discharge A CV provided with a power source for supplying electric power for glow discharge generation to the electrodes, and a supporting electrode which is arranged in the reaction vessel in parallel with the discharging ladder type electrode with a space therebetween and which has a built-in heater for heating.
Using the D device, at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer of the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure is formed on the support electrode of the CVD device by the transparent insulation. The object to be processed having a flexible substrate is heated while supporting SiH ₄ and SiH ₂
A mixed gas of at least one silicon chlorinated compound gas selected from Cl ₂ , SiHCl ₃ and SiCl ₄ and H ₂ is supplied as the raw material gas from the gas supply means into the reaction vessel, and a ladder type from the power source. It is characterized in that the film is formed by supplying glow discharge generating power having a frequency of 60 MHz or more to the electrodes to cause glow discharge in the reaction vessel to generate plasma.

The solar cell according to the present invention comprises a first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, a second transparent electrode, and a back electrode on a transparent insulating substrate. In a solar cell in which light is incident from the transparent insulating substrate side.
Of the microcrystalline silicon layer or the polycrystalline silicon layer having the n structure or the nip structure, at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer contains 1 × 10 ¹⁸ c of chlorine.
It is characterized by containing m ⁻³ to 8 × 10 ²⁰ cm ⁻³ .

Another solar cell according to the present invention comprises a back electrode, a first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, and a second transparent electrode on a transparent insulating substrate. In the solar cell in which electrodes are sequentially formed and light is incident from the second transparent electrode side,
Of the microcrystalline silicon layer or the polycrystalline silicon layer having the in structure or the nip structure, at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer contains 1 × 10 ¹⁸ chlorine.
It is characterized by containing cm ^-3 to 8 × 10 ²⁰ cm ^-3 .

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

FIG. 1 is a schematic view showing a plasma CVD apparatus used for forming a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure in the production of solar cells according to the embodiments described below. 2 is Figure 1
FIG. 3 is a perspective view showing a discharge ladder electrode incorporated in the CVD apparatus of FIG.

A discharge ladder 2 having the structure shown in FIG. 2 is arranged upright in the grounded reaction vessel 1. The anode 3 having a built-in heater (not shown) is arranged in the reaction vessel 1 in parallel with the ladder electrode 2 with a desired distance. In such an arrangement of the ladder-shaped electrode 2 and the anode 3, the opposing surface thereof is referred to as a front surface, and the opposite surface is referred to as a rear surface. The anode 3 has a function of holding a substrate to be processed.

The high frequency power source 4 includes an impedance matching device 5
Is connected to the ladder type electrode 2 through. A gas supply pipe 6 for supplying a raw material gas is inserted into the reaction vessel 1 such that its tip is located on the back surface of the ladder electrode 2. The exhaust pipe 7 is connected to the side surface of the reaction vessel 1 located on the back surface of the anode 3, and the other end thereof is connected to an exhaust member such as a vacuum pump (not shown).

(First Embodiment) A method of manufacturing a solar cell of the type in which light is incident from the transparent insulating substrate side according to the present invention will be described with reference to the plasma CVD apparatus shown in FIGS.

(First Step) A first transparent electrode is formed on a transparent insulating substrate.

The transparent insulating substrate is made of, for example, soda-lime glass showing light transmission.

The first transparent electrode is, for example, tin oxide (Sn).
O _2), is made from a metal oxide such as indium tin oxide (ITO). Here, in order to suppress reduction of the first transparent electrode by hydrogen, a zinc oxide film (not shown) having a thickness of several tens nm is formed on the first transparent electrode.

(Second Step) The transparent insulating substrate having the first transparent electrode formed thereon is held as the object 8 to be processed by the anode 3 of the plasma CVD apparatus shown in FIG.
After connecting to the grounded reaction vessel 1 through the lead,
A vacuum pump (not shown) is operated to evacuate the inside of the reaction vessel 1 through the exhaust pipe 7. Subsequently, the heater incorporated in the anode 3 is energized to heat the substrate of the object 8 to be treated to a desired temperature. After the heating temperature by the heater is sufficiently stabilized, the raw material gas, Si, is placed in the reaction vessel 1.
H ₄ , H ₂ and p-type impurity gas are introduced through the gas supply pipe 6 to control the inside of the reaction vessel 1 to a predetermined pressure. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, high-frequency power is supplied from the high-frequency power source 4 to the discharge ladder-type electrode 2 through the impedance matching device 5, so that the discharge ladder-type electrode 2 and the object to be treated 8 are provided. A plasma 9 is generated between them to form a p-type microcrystalline Si layer or a polycrystalline Si layer on the first transparent electrode of the object to be processed 8.

As the p-type impurity, for example, B ₂ H ₆ or the like can be used.

(Third Step) After forming the p-type microcrystalline Si layer or the polycrystalline Si layer, the supply of the raw material gas is stopped and the inside of the reaction vessel 1 is evacuated. Subsequently, a mixed gas of at least one silicon chlorinated compound gas selected from SiH ₄ and SiH ₂ Cl ₂ , SiHCl ₃ and SiCl ₄ which is a raw material gas and H ₂ is fed into the reaction vessel 1 through a gas supply pipe 6. It is introduced and controlled to a predetermined pressure in the reaction vessel 1.
After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, a high frequency power having a frequency of 60 MHz or more is supplied from the high frequency power source 4 to the discharge ladder type electrode 2 through the impedance matching device 5 so that the discharge ladder type electrode 2 and A plasma 9 is generated between the object 8 to be processed,
The i-type microcrystalline Si layer or the polycrystalline Si layer is formed on the p-type microcrystalline Si layer or the polycrystalline Si layer.

By adding the chlorinated silicon compound gas to the raw material gas, the transparent insulating substrate of the object to be treated by the heater of the anode 3 is heated at a relatively low temperature of 120 to 300 ° C. ( 110) It becomes possible to form an i-type microcrystalline Si layer or a polycrystalline Si layer having preferential orientation. When the heating temperature of this transparent insulating substrate is set to less than 120 ° C., it may be difficult to form an i-type microcrystalline Si layer or a polycrystalline Si layer having (110) preferential orientation. On the other hand, the heating temperature of the transparent insulating substrate is 3
When the temperature is higher than 00 ° C., hydrogen radicals in plasma derived from SiH ₄ gas at the time of film formation diffuse in the p-type microcrystalline Si layer or polycrystalline Si layer, and are further made of a metal oxide on the lower side. 1 When reaching the transparent electrode and reducing, oxygen is extracted from the metal oxide, light transmittance is reduced, photoelectric conversion efficiency is reduced, and p-type microcrystalline Si layer or polycrystalline Si layer There is a possibility that the p-type impurities may diffuse into the pi junction interface to deteriorate the electrical characteristics and reduce the photoelectric conversion efficiency.

The silicon chlorinated compound gas is the S
It is preferable that the iH ₄ and the silicon chlorinated compound gas are supplied to the reaction vessel 1 at a flow rate ratio of 1 to 80% with respect to the total flow rate. When the flow rate ratio of the silicon chlorinated compound gas is less than 1%, the i-type microcrystal S having a good film quality is obtained under a relatively low temperature heating condition of 120 to 300 ° C.
It becomes difficult to form the i layer or the polycrystalline Si layer.
On the other hand, the flow ratio of the silicon chlorinated compound gas is 80%.
If it exceeds, the i-type microcrystalline Si layer or the polycrystalline Si layer becomes C
There is a possibility that the film formation rate may be reduced by etching with 1, 1, Cl ₂ or the like, and that the i-type Si layer may become amorphous. More preferable flow ratio of the silicon chlorinated compound gas is 10%.
-40%.

By setting the flow rate ratio of the silicon chlorinated compound gas to 1 to 80%, the chlorine content is 1 × 10 ¹⁸ cm 2.
It becomes possible to form an i-type microcrystalline Si layer or a polycrystalline Si layer containing ⁻³ to 8 × 10 ²⁰ cm ⁻³ . The chlorine content in the i-type microcrystalline Si layer or polycrystalline Si layer is set to 1
When it is less than × 10 ¹⁸ cm ^−3, it becomes difficult to improve the (110) preferred orientation in the i-type microcrystalline Si layer or the polycrystalline Si layer. On the other hand, if the chlorine content in the i-type microcrystalline Si layer or the polycrystalline Si layer exceeds 8 × 10 ²⁰ cm ⁻³ , the film quality of the i-type microcrystalline Si layer or the polycrystalline Si layer may be deteriorated. There is. More preferable i-type microcrystalline Si
Chlorine content in layer or polycrystalline Si layer is 2 × 10 ¹⁹ cm
^{-3 it is} ~4 × 10 ²⁰ cm ^-3. When mixing the silicon chlorinated compound gas with SiH ₄ and H ₂ ,
Allow the use of gas diluted with ₂ .

The pressure at which plasma is generated in the reaction vessel is preferably set in the range of 0.5 to 10 Torr, more preferably 0.5 to 3.0 Torr.

(Fourth Step) After forming the i-type microcrystalline Si layer or the polycrystalline Si layer, the supply of the raw material gas is stopped and the inside of the reaction vessel 1 is evacuated. Next, this reaction container 1
Source gases SiH ₄ , H ₂ and n-type impurity gas (PH ₃ etc.) are introduced through the gas supply pipe 6 to control the pressure in the reaction vessel 1 to a predetermined pressure. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, high-frequency power is supplied from the high-frequency power source 4 to the discharge ladder-type electrode 2 through the impedance matching device 5, so that the discharge ladder-type electrode 2 and the object to be treated 8 are provided. A plasma 9 is generated during the process to form an n-type microcrystalline Si layer or a polycrystalline Si layer on the i-type microcrystalline Si layer or the polycrystalline Si layer of the object to be processed 8. Thereafter, the object to be processed is taken out from the reaction vessel 1 having the plasma CVD layer, and the second transparent electrode and the back surface electrode are sequentially formed on the n-type microcrystalline Si layer or the polycrystalline Si layer to manufacture a solar cell. . This solar cell is generated by causing light such as sunlight to enter from the transparent insulating substrate side and photoelectrically converting the light in the microcrystalline Si layer or the polycrystalline Si layer having the pin structure.

As the n-type impurity gas, for example, PH
₃ etc. can be used.

The second transparent electrode is made of, for example, indium tin oxide (ITO) or tin oxide.

The back electrode is made of, for example, Al.

In the manufacture of the solar cell, a p-type, i-type, and n-type microcrystalline Si layers were sequentially formed from the first transparent electrode side to form a pin structure. The microcrystalline silicon layer or the polycrystalline silicon layer of
It may have a p structure.

The arrangement of p, i, n between the first transparent electrode and the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure is the microcrystalline silicon layer or the polycrystalline silicon layer. It is allowed to place an amorphous silicon layer having a pin structure or a nip structure similar to the layer.

As described above, according to the first embodiment, the first transparent electrode, the microcrystalline Si layer or the polycrystalline Si layer having the pin structure or the nip structure, the second transparent electrode and the back electrode are sequentially formed on the transparent insulating substrate. Then, in manufacturing a solar cell having a structure in which light is incident from the transparent insulating substrate side, SiH ₄ and SiH ₂ are supported by heating a workpiece having the transparent insulating substrate on a supporting electrode of a plasma CVD apparatus. Cl ₂ ,
At least 1 selected from SiHCl ₃ and SiCl ₄
A mixed gas of one silicon chlorinated compound gas and H ₂ is supplied as a raw material gas from the gas supply means into the reaction vessel, and power for glow discharge generation with a frequency of 60 MHz or more is supplied from the power source to the ladder type electrode. A glow discharge is generated in the reaction vessel to generate plasma, whereby a p-type (or n-type) microcrystalline Si layer or polycrystalline S layer is formed.
It becomes possible to form an i-type microcrystalline Si layer or a polycrystalline Si layer having (110) preferential orientation under heating conditions of the i layer at a relatively low temperature of 120 to 300 ° C.

That is, when a silicon chlorinated gas such as SiH ₂ Cl ₂ is used as one component of the source gas, the silicon chlorinated gas is decomposed in plasma to generate chlorine, so that the growth surface of silicon is Can be covered with chlorine instead of hydrogen. Since chlorine has a larger atomic size than hydrogen, it is difficult to be taken into the Si layer, and (11
0) Generation of secondary nuclei that hinder the orientation can be suppressed. As a result, it becomes possible to form an i-type microcrystalline Si layer or a polycrystalline Si layer having a (110) preferential orientation.

Therefore, when the i-type microcrystalline Si layer or the polycrystalline Si layer is formed, the hydrogen radicals in the plasma derived from SiH ₄ gas are the p-type (or n-type) microcrystalline S.
It is possible to suppress the reaction of diffusing the i layer or the polycrystalline Si layer and further reaching the first transparent electrode made of a metal oxide such as tin oxide on the lower side and reducing the first transparent electrode. As a result, the extraction of oxygen from the metal oxide can be suppressed, and the light transmittance of the first transparent electrode can be maintained.

In addition, an i-type microcrystalline Si layer or polycrystalline S
Suppressing diffusion of p-type (or n-type) impurities at the pi-junction interface (or ni-junction interface) with the p-type (or n-type) microcrystalline Si layer or polycrystalline Si layer during the formation of the i-layer Therefore, the electrical characteristics at the bonding interface can be maintained in a good state.

As described above, according to the first embodiment, the i-type microcrystalline Si having the (110) preferential orientation at a relatively low temperature is used.
Layer or a polycrystalline Si layer can be formed, the light transmittance of the first transparent electrode can be maintained, and the electrical characteristics at the pi junction interface (or ni junction interface) can be maintained in a good state. Therefore, when light such as sunlight is incident from the transparent insulating substrate side, a solar cell exhibiting high photoelectric conversion efficiency can be manufactured.

The first transparent electrode, the pin structure or n
microcrystalline Si layer or polycrystalline Si layer having ip structure, second
In a solar cell having a structure in which a transparent electrode and a back electrode are sequentially formed and light is incident from the transparent insulating substrate side, i
-Type microcrystalline Si layer or polycrystalline Si layer with an amount of chlorine of 1 ×
By specifying 10 ¹⁸ to 8 × 10 ²⁰ cm ⁻³ ,
Since the (110) preferential orientation can be improved, a solar cell exhibiting high photoelectric conversion efficiency can be obtained when light such as sunlight enters from the transparent insulating substrate side.

Further, between the first transparent electrode and the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure, the arrangement of p, i, and n is the microcrystalline Si layer or the polycrystalline Si layer. Pin structure similar to layers or n
By arranging the amorphous silicon layer having the ip structure, a solar cell having higher photoelectric conversion efficiency can be obtained.

(Second Embodiment) A method of manufacturing a solar cell of the type in which light is incident from the second transparent electrode side according to the present invention will be described with reference to the plasma CVD apparatus shown in FIGS. 1 and 2 described above.

(First step) After forming a back electrode made of, for example, Al on a transparent insulating substrate made of soda-lime glass showing light transmission, for example, tin oxide, indium tin oxide (ITO), etc. are formed on the back electrode. Forming a first transparent electrode made of a metal oxide such as.

(Second Step) The plasma shown in FIG. 1 described above.
A transparent electrode having the first transparent electrode formed on the anode 3 of the CVD apparatus.
The bright insulating substrate is held as the object to be processed 8
After connecting to the grounded reaction vessel 1 through the lead,
The vacuum pump (not shown) is operated to pass the exhaust pipe 7
The gas in the reaction container 1 is evacuated. Next, anode 3
The heating heater built in the
The substrate is heated to the desired temperature. Heating temperature by heater
After the temperature is sufficiently stabilized, the raw material gas S
iH _Four, H₂And for example PH₃N-type impurity gas such as
Is introduced through the gas supply pipe 6, and the inside of the reaction vessel 1 is
Control to pressure. The temperature and pressure inside the reaction vessel 1 are sufficient
After stabilizing, the high frequency power from the high frequency power source 4
Supply to the discharge ladder electrode 2 through the impedance matching device 5.
As a result, the discharge ladder electrode 2 and the object to be treated 8
A plasma 9 is generated between
Produces n-type microcrystalline Si layer or polycrystalline Si layer on bright electrode
To film.

(Third Step) After forming the n-type microcrystalline Si layer or polycrystalline Si layer, the supply of the raw material gas is stopped and the inside of the reaction vessel 1 is evacuated. Subsequently, a mixed gas of at least one silicon chlorinated compound gas selected from SiH ₄ and SiH ₂ Cl ₂ , SiHCl ₃ and SiCl ₄ which is a raw material gas and H ₂ is fed into the reaction vessel 1 through a gas supply pipe 6. It is introduced and controlled to a predetermined pressure in the reaction vessel 1.
After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, a high frequency power having a frequency of 60 MHz or more is supplied from the high frequency power source 4 to the discharge ladder type electrode 2 through the impedance matching device 5 so that the discharge ladder type electrode 2 and A plasma 9 is generated between the object 8 to be processed,
The i-type microcrystalline Si layer or the polycrystalline Si layer is formed on the n-type microcrystalline Si layer or the polycrystalline Si layer.

By adding the chlorinated silicon compound gas to the raw material gas, the transparent insulating substrate of the object to be treated by the heater of the anode 3 is heated at a relatively low temperature of 120 to 300 ° C. ( 110) It becomes possible to form an i-type microcrystalline Si layer or a polycrystalline Si layer having preferential orientation. When the heating temperature of this transparent insulating substrate is set to less than 120 ° C., it may be difficult to form an i-type microcrystalline Si layer or a polycrystalline Si layer having (110) preferential orientation. On the other hand, the heating temperature of the transparent insulating substrate is 3
When the temperature is higher than 00 ° C., hydrogen radicals in plasma derived from SiH ₄ gas at the time of film formation diffuse in the n-type microcrystalline Si layer or polycrystalline Si layer, and are further made of a metal oxide on the lower side. 1 When reaching the transparent electrode and reducing, oxygen is extracted from the metal oxide, light transmittance is reduced, photoelectric conversion efficiency is reduced, and n-type microcrystalline Si layer or polycrystalline Si layer There is a risk that the n-type impurities may diffuse into the ni junction interface to deteriorate the electrical characteristics, resulting in a decrease in photoelectric conversion efficiency.

The silicon chlorinated compound gas is the S
It is preferable that the iH ₄ and the silicon chlorinated compound gas are supplied to the reaction vessel 1 at a flow rate ratio of 1 to 80% with respect to the total flow rate. When the flow rate ratio of the silicon chlorinated compound gas is less than 1%, i-type microcrystalline Si having a good film quality under heating conditions of a relatively low temperature of 120 to 300 ° C.
It becomes difficult to form a layer or a polycrystalline Si layer. On the other hand, when the flow rate ratio of the silicon chlorinated compound gas exceeds 80%, the i-type microcrystalline Si or polycrystalline Si layer becomes Cl,
Etching with Cl ₂ or the like reduces the film forming rate, and i
The type Si layer may become amorphous. More preferable flow ratio of the silicon chlorinated compound gas is 10% to 4
It is 0%.

By setting the flow rate ratio of the silicon chlorinated compound gas to 1 to 80%, the chlorine content is 1 × 10 ¹⁸ cm 2.
It becomes possible to form an i-type microcrystalline Si layer or a polycrystalline Si layer containing ⁻³ to 8 × 10 ²⁰ cm ⁻³ . The chlorine content in the i-type microcrystalline Si layer or polycrystalline Si layer is set to 1
When it is less than × 10 ¹⁸ cm ^−3, it becomes difficult to improve the (110) preferred orientation in the i-type microcrystalline Si layer or the polycrystalline Si layer. On the other hand, if the chlorine content in the i-type microcrystalline Si layer or the polycrystalline Si layer exceeds 8 × 10 ²⁰ cm ⁻³ , the film quality of the i-type microcrystalline Si layer or the polycrystalline Si layer may be deteriorated. There is. More preferable i-type microcrystalline Si
Chlorine content in layer or polycrystalline Si layer is 2 × 10 ¹⁹ cm
^{-3 it is} ~4 × 10 ²⁰ cm ^-3. When mixing the silicon chlorinated compound gas with SiH ₄ and H ₂ ,
Allow to dilute by ₂ .

The pressure at which plasma is generated in the reaction vessel is preferably set in the range of 0.5 to 10 Torr, more preferably 0.5 to 3.0 Torr.

The high frequency power supplied from the high frequency power source to the discharge ladder electrode preferably has a frequency of 60 MHz or higher.

(Fourth Step) After forming the i-type microcrystalline Si layer or the polycrystalline Si layer, the supply of the raw material gas is stopped and the inside of the reaction vessel 1 is evacuated. Next, this reaction container 1
A source gas such as SiH and H and a p-type impurity gas such as B ₂ H ₆ are introduced into the reaction vessel through a gas supply pipe 6, and the reaction vessel 1 is controlled to a predetermined pressure. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, high-frequency power is supplied from the high-frequency power source 4 to the discharge ladder-type electrode 2 through the impedance matching device 5, so that the discharge ladder-type electrode 2 and the object to be treated 8 are provided. A plasma 9 is generated during this period to form a p-type microcrystalline Si layer or polycrystalline Si layer on the i-type microcrystalline Si layer or polycrystalline Si layer of the object to be processed 8.
After that, the object to be treated is put into a reaction vessel 1 for plasma CVD layer.
From the p-type microcrystalline Si layer or polycrystalline S
A second transparent electrode made of a metal oxide such as tin oxide or indium tin oxide (ITO) is formed on the i layer to manufacture a solar cell. In this solar cell, light such as sunlight is made incident from the second transparent electrode side to obtain the pin-structured microcrystal S.
Electromotive force is generated by photoelectric conversion in the i layer or the polycrystalline Si layer.

In the manufacture of the solar cell, n-type, i-type and p-type microcrystalline Si layers were sequentially formed from the first transparent electrode side to form a nip structure. The microcrystalline Si layer or the polycrystalline Si layer may be sequentially formed into a pin structure.

Further, between the microcrystalline Si layer or the polycrystalline Si layer having the nip structure or the pin structure and the second transparent electrode, the arrangement of p, i, n is the microcrystalline Si layer or the polycrystalline Si layer. It is allowed to place an amorphous silicon layer having a nip structure or a pin structure similar to the layer.

As described above, according to the second embodiment, the back surface electrode, the first transparent electrode, the nip structure or the pi is formed on the transparent insulating substrate.
Plasma CVD in the manufacture of a solar cell having a structure in which a microcrystalline Si layer or a polycrystalline Si layer having an n structure and a second transparent electrode are sequentially formed and light is incident from the second transparent electrode side.
An object to be processed having the transparent insulating substrate is supported on a supporting electrode of the apparatus and heated to produce SiH ₄ , SiH ₂ Cl ₂ , and SiH.
A mixed gas of at least one silicon chlorinated compound gas selected from Cl ₃ and SiCl ₄ and H ₂ is supplied as a raw material gas from the gas supply means into the reaction vessel, and a frequency of 60 MHz or more is supplied from the power source to the ladder electrode. Of the glow discharge generation power to cause glow discharge in the reaction vessel to generate plasma, and thereby 120 to 300 ° C. on the n-type (or p-type) microcrystalline Si layer or polycrystalline Si layer. The i-type microcrystalline Si layer or the polycrystalline Si layer having the (110) preferential orientation can be formed by the same operation as that of the first embodiment described above under the heating condition of relatively low temperature.

Therefore, hydrogen radicals in the plasma derived from SiH ₄ gas diffuse in the n-type microcrystalline Si layer or the polycrystalline Si layer when the i-type microcrystalline Si layer or the polycrystalline Si layer is formed, Further, it is possible to suppress the reaction of reaching and reducing the first transparent electrode made of a metal oxide such as tin oxide on the lower side. As a result, the extraction of oxygen from the metal oxide can be suppressed, and the light transmittance of the first transparent electrode can be maintained.

Further, i-type microcrystalline Si layer or polycrystalline S layer
Suppressing diffusion of n-type (or p-type) impurities at the ni-junction interface (or pi-junction interface) with the n-type (or p-type) microcrystalline Si layer or polycrystalline Si layer during the formation of the i-layer Therefore, the electrical characteristics at the bonding interface can be maintained in a good state.

As described above, according to the second embodiment, i-type microcrystalline Si having a (110) preferential orientation at a relatively low temperature.
Layer or a polycrystalline Si layer can be formed, the light transmittance of the first transparent electrode can be maintained, and the electrical characteristics at the ni junction interface (or pi junction interface) can be maintained in a good state. Therefore, when light such as sunlight is incident from the second transparent electrode side, it is possible to manufacture a solar cell that exhibits high photoelectric conversion efficiency.

Also, a back electrode, a first electrode, and a transparent insulating substrate are provided.
Microcrystal S having transparent electrode, nip structure or pin structure
In a solar cell having a structure in which an i layer or a polycrystalline Si layer and a second transparent electrode are sequentially formed and light is incident from the second transparent electrode side, the amount of chlorine in the i-type microcrystalline Si layer or the polycrystalline Si layer by defining the ^{1 × 10 18 ~8 × 10 20} cm -3 , and (110) because it can improve the preferential orientation, when the incident light such as sunlight from the second transparent electrode side, high photoelectric conversion A solar cell exhibiting efficiency can be obtained.

Furthermore, the arrangement of p, i, and n between the microcrystalline Si layer or the polycrystalline Si layer having the nip structure or the pin structure and the second transparent electrode is the microcrystalline Si layer or the polycrystalline Si layer. By arranging an amorphous silicon layer having a nip structure or a pin structure similar to that of a layer, a solar cell having higher photoelectric conversion efficiency can be obtained.

[0061]

Embodiments of the present invention will now be described in detail with reference to the drawings.

(Embodiment 1) In Embodiment 1, a manufacturing process of a solar cell of a type in which light is incident from the transparent insulating substrate side and having a pin structure made of microcrystalline Si will be described with reference to FIGS.

First, the first transparent electrode 12 made of tin oxide (SnO ₂ ) was formed on the transparent insulating substrate 11 made of soda-lime glass having light transmission.

Next, the plasma CV shown in FIG.
Reaction in which the transparent insulating substrate 11 having the transparent electrode 12 formed thereon is held as an object 8 to be processed in the anode 3 in the reaction container 1 for p-layer film formation in the D apparatus, and the object 8 is grounded through a lead. After connecting to the container 1, a vacuum pump (not shown) is operated to move the inside of the reaction container 1 through the exhaust pipe 7 to 1 × 1.
0 ^- The following was evacuated to ⁸ Torr. Next, anode 3
The heating heater incorporated in the substrate was energized to heat the substrate of the object to be treated 8 to a temperature of 160 ° C. After the heating temperature by the heater was sufficiently stabilized, the raw material gases SiH ₄ , H ₂ and B ₂ H ₆ were introduced into the reaction vessel 1 through the gas supply pipe 6, and the pressure inside the reaction vessel 1 was controlled to 500 mTorr. . After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, a high-frequency power having a frequency of 100 MHz is supplied from the high-frequency power source 4 to the discharge ladder-shaped electrode 2 through the impedance matching device 5, so that the discharge ladder-shaped electrode 2 and the cover Plasma 9 was generated between the processed objects 8 to form a p-type microcrystalline Si layer 13 having a thickness of 30 nm on the first transparent electrode 12 of the processed object 8.

Next, after the p-type microcrystalline Si layer 13 is formed,
The supply of the raw material gas was stopped and the inside of the reaction vessel 1 was evacuated. Subsequently, the object to be treated 8 is placed in the reaction container 1 for forming the i-layer.
Was moved and set in the same procedure as the above film formation. 1 x 10
After evacuating to ⁻⁷ Torr or less, the heater of the anode 3 was then energized to heat the substrate of the object to be treated 8 to 190 ° C. After the heating temperature by the heater is sufficiently stabilized, the raw material gas, Si, is placed in the reaction vessel 1.
After introducing a mixed gas of H ₄ , SiH ₂ Cl ₂ and H ₂ through the gas supply pipe 6, the pressure in the reaction vessel 1 was controlled to 2 Torr. At this time, the amount of each gas is SiH _4:. 3 to
7 sccm, SiH ₂ Cl ₂ (diluted with 1% hydrogen): 50 to 2
00sccm, H _2: was 100~250sccm.
Further, SiH ₂ Cl ₂ was in the range of 10 to 40% in flow rate with respect to the flow rate of all Si gas. After introducing the raw material gas, after sufficiently stabilizing the temperature and pressure in the reaction vessel 1,
The high frequency power source 4 passes through the impedance matching device 5 and the discharge ladder electrode 2 has a frequency of 100 MHz and 70 mW / c.
Plasma is generated by supplying high-frequency power of m ² to a thickness of 1500 nm on the p-type microcrystalline Si layer 13.
The i-type microcrystalline Si layer 14 was deposited. This i-type microcrystal S
The i layer 14 contained 6 × 10 ¹⁹ cm ^{−3 of} chlorine.

Next, after forming the i-type microcrystalline Si layer 14,
The supply of the raw material gas was stopped and the inside of the reaction vessel 1 was evacuated. Subsequently, the object to be treated 8 is placed in the reaction container 1 for n-layer film formation.
Was moved and set by the same procedure. 1 x 10 ^-7 Torr
After evacuating to the following, the heater built in the anode 3 is then energized to remove 160
Heated to ° C. After the heating temperature by the heater is sufficiently stabilized, SiH ₄ , which is a raw material gas, is charged in the reaction vessel 1.
H ₂ and PH ₃ were introduced through the gas supply pipe 6, and the pressure inside the reaction vessel 1 was controlled to 700 mTorr. After the temperature and pressure inside the reaction vessel 1 are sufficiently stabilized, the high frequency power source 4
Is supplied to the discharge ladder electrode 2 through the impedance matching device 5 to generate plasma 9 between the discharge ladder electrode 2 and the object 8 to be processed, and the i-type of the object 8 to be processed is generated. Thickness 3 on the microcrystalline Si layer 14
A 0 nm n-type microcrystalline Si layer 15 was formed. After that, the object to be processed is taken out from the reaction vessel 1 of the plasma CVD layer, and the indium oxide (IT
The second transparent electrode 16 made of O) and the back electrode 17 made of Al were sequentially formed to manufacture the solar cell shown in FIG.

(Comparative Example 1) SiH ₄ (flow rate: _{4 to} 8 sccm) and H ₂ (flow rate:
(250-350 sccm) is introduced through the gas supply pipe 6, the pressure in the reaction vessel 1 is controlled to 2 Torr, the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, and then the high frequency power source 4 discharges through the impedance matching device 5. A plasma is generated by supplying high frequency power of 70 mW / cm ^{2 at} a frequency of 100 MHz to the ladder electrode 2,
I-type microcrystalline Si having a thickness of 1500 nm on the i-type microcrystalline Si layer
A solar cell was manufactured in the same manner as in Example 1 except that the layer 14 was formed.

The (110) orientation ratio of the i-type microcrystalline Si layer formed in Example 1 and Comparative Example 1 was examined. The results are shown in Table 1 below.

[0069]

[Table 1]

As is clear from Table 1 above, SiH ₂ Cl ₂
The i-type microcrystalline Si layer of Example 1 formed by using the raw material gas added in the range of 10 to 40% in flow rate with respect to the flow rate of the total Si gas does not contain SiH ₂ Cl ₂ and does not contain SiH _{2. I of} Comparative Example 1 in which a film was formed using a source gas composed of ₄ and H _2.
It can be seen that the (110) orientation ratio shows a value of 29, which is 5 times or more that of the type microcrystalline Si layer.

In addition, simulated solar light (spectrum: AM1.5, irradiation intensity: 1) was applied to the solar cells of Example 1 and Comparative Example 1.
(00 mW / cm ² , sample temperature: room temperature) was made incident from the transparent insulating substrate side to evaluate the power generation characteristics. The result is shown in FIG.

As is clear from FIG. 4, the solar cell of Example 1 has an improved short-circuit current as compared with the solar cell of Comparative Example 1. This is because the (110) orientation ratio of the i-type microcrystalline Si layer forming the solar cell of Example 1 was improved.

(Embodiment 2) In Embodiment 2, a manufacturing process of a solar cell of a type in which light is incident from the transparent insulating substrate side and having a pin structure made of polycrystalline Si will be described with reference to FIGS.

First, the first transparent electrode 1 made of tin oxide is formed on the transparent insulating substrate 11 made of soda-lime glass having light transmission.
Formed 2.

Next, the plasma CV shown in FIG.
Reaction container in which the transparent insulating substrate 11 having the transparent electrode 12 formed thereon is held as the object to be processed 8 on the anode 3 in the reaction container 1 for p-layer film formation in the D apparatus, and the object to be processed 8 is grounded through a lead. 1 is connected to the inside of the reaction vessel 1 through an exhaust pipe 7 by operating a vacuum pump (not shown).
^It was evacuated to below ^-8 Torr. Subsequently, the heater incorporated in the anode 3 was energized to heat the substrate of the object 8 to be treated to a temperature of 180 ° C. After the heating temperature by the heater was sufficiently stabilized, the raw material gases SiH ₄ , H ₂ and B ₂ H ₆ were introduced into the reaction vessel 1 through the gas supply pipe 6, and the pressure inside the reaction vessel 1 was controlled to 500 mTorr. . After the temperature and pressure inside the reaction vessel 1 are sufficiently stabilized,
By supplying high frequency power having a frequency of 100 MHz from the high frequency power source 4 to the discharging ladder electrode 2 through the impedance matching device 5, plasma 9 is generated between the discharging ladder electrode 2 and the object 8 to be treated, Treated product 8
Of p-type polycrystalline S having a thickness of 300 nm on the first transparent electrode 12 of
The i layer 18 was formed into a film.

Next, after the p-type polycrystalline Si layer 18 is formed,
The supply of the raw material gas was stopped and the inside of the reaction vessel 1 was evacuated. Subsequently, the object to be treated 8 is placed in the reaction container 1 for forming the i-layer.
Was moved and set in the same procedure as the above film formation. 1 x 10
After evacuating to ^-7 Torr or less, the heater of the anode 3 was energized to heat the substrate of the article 8 to be heated to 210 ° C. After the heating temperature by the heater is sufficiently stabilized, the raw material gas, Si, is placed in the reaction vessel 1.
After introducing a mixed gas of H ₄ , SiH ₂ Cl ₂ and H ₂ through the gas supply pipe 6, the pressure in the reaction vessel 1 was adjusted to 1.0 Torr.
Controlled to r. At this time, the amount of each gas is SiH ₄ :
5-10 sccm, SiH ₂ Cl ₂ (diluted with 1% hydrogen): 1
00-200 sccm, H ₂ : 100-200 sccm
And Further, SiH ₂ Cl ₂ was in the range of 10 to 30% in flow rate ratio with respect to the flow rate of all Si gas. After introducing the raw material gas and sufficiently stabilizing the temperature and pressure in the reaction vessel 1, a frequency 100 MHz, 100
A plasma is generated by supplying a high frequency power of mW / cm ² , and a thickness of 15 is formed on the p-type polycrystalline Si layer 18.
An i-type polycrystalline Si layer 19 of 00 nm was formed. The i-type polycrystalline Si layer 18 contained chlorine at 4 × 10 ¹⁹ cm ⁻³ .

Next, after forming the i-type polycrystalline Si layer 19,
The supply of the raw material gas was stopped and the inside of the reaction vessel 1 was evacuated. Subsequently, the object to be treated 8 is placed in the reaction container 1 for n-layer film formation.
Was moved and set in the same procedure as the above film formation. 1 x 10
After evacuation to ^-7 Torr or less, the heater of the anode 3 was then energized to heat the substrate of the object 8 to be processed to 180 ° C. After the heating temperature by the heater was sufficiently stabilized, raw material gases SiH ₄ , H ₂ and PH ₃ were introduced into the reaction vessel 1 through the gas supply pipe 6, and the pressure inside the reaction vessel 1 was controlled to 700 mTorr. After the temperature and pressure inside the reaction vessel 1 are sufficiently stabilized,
Impedance matching device 5 receives high frequency power from high frequency power source 4
Through the discharge ladder electrode 2 to generate plasma 9 between the discharge ladder electrode 2 and the object 8 to be processed, and the i-type polycrystalline Si layer 1 of the object 8 to be processed
An n-type polycrystalline Si layer 20 having a thickness of 30 nm was formed on the film 9. After that, the object to be processed is taken out from the reaction container 1 of the plasma CVD layer, and the second transparent electrode 16 made of indium oxide and the back electrode 17 made of Al are sequentially formed on the n-type polycrystalline Si layer 20 to form a structure shown in FIG. The solar cell shown in was manufactured.

As a result of examining the (110) orientation ratio of the i-type polycrystalline Si layer formed in Example 2, the same 29 as in Example 1 was obtained.
The value of was shown.

In addition, simulated solar light (spectrum: AM1.5, irradiation intensity: 100 mW / c) was applied to the solar cell of Example 2.
(m ² , irradiation temperature: room temperature) was incident from the transparent insulating substrate side to evaluate the power generation characteristics. As a result, a large short circuit current similar to that of Example 1 was obtained.

(Embodiment 3) In this embodiment 3, a process of manufacturing a solar cell having a tandem structure in which a pin structure is made of microcrystalline Si and light is incident from the transparent insulating substrate side is referred to FIG. And explain.

First, the first transparent electrode 1 made of tin oxide is formed on the transparent insulating substrate 11 made of soda-lime glass having light transmission.
Formed 2.

Next, the plasma CV shown in FIG.
The transparent electrode 1 is provided on the anode 3 in the reaction vessel 1 of the D apparatus.
The transparent insulative substrate 11 on which 2 is formed is held as an object to be processed 8, the object to be processed 8 is connected to the reaction container 1 which is grounded through a lead, and then a vacuum pump (not shown) is operated to pass through the exhaust pipe 7 and 1 × 10 ^-8 Torr in the reaction vessel 1
The following was evacuated. Then, the heater incorporated in the anode 3 is energized to heat the substrate of the object 8 to be treated at 130 ° C.
Heated to the temperature of. After the heating temperature by the heater is sufficiently stabilized, SiH ₄ , which is the source gas, is placed in the reaction vessel 1.
H ₂ and B ₂ H ₆ were introduced through the gas supply pipe 6, and the pressure inside the reaction vessel 1 was controlled to 100 mTorr. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, a high frequency power of 13.56 MHz is supplied from the high frequency power source 4 to the discharging ladder type electrode 2 through the impedance matching device 5 and the discharging ladder type electrode 2. A plasma 9 is generated between the object 8 to be processed,
30 nm thick p-type amorphous Si on the transparent electrode 12
The layer 31 was formed into a film.

Next, after the p-type amorphous Si layer 31 was formed, the supply of the raw material gas was stopped and the inside of the reaction vessel 1 was evacuated. Subsequently, the object to be treated 8 was moved into the reaction container 1 for forming the i-layer and set in the same procedure as the above-mentioned film formation. 1 x
After evacuating to 10 ^-7 Torr or less, the heater built in the anode 3 is then energized to produce the object 8 to be treated.
The substrate was heated to 160 ° C. After the heating temperature by the heater is sufficiently stabilized, SiH ₄ (flow rate: 50 sccm) and H ₂ (flow rate: 50) which are raw material gases are placed in the reaction vessel 1.
sccm) was introduced through the gas supply pipe 6, the pressure in the reaction vessel 1 was controlled to 100 mTorr. After the raw material gas is introduced, the temperature and pressure inside the reaction vessel 1 are sufficiently stabilized, and then the high frequency power source 4 passes through the impedance matching device 5 to the discharge ladder electrode 2 at a frequency of 60 MHz, 20
Plasma was generated by supplying a high-frequency power of 0 mW / cm ² to form an i-type amorphous Si layer 32 having a thickness of 300 nm on the p-type amorphous Si layer 31.

Next, after forming the i-type amorphous Si layer 32, the supply of the raw material gas was stopped and the inside of the reaction vessel 1 was evacuated. Subsequently, the object to be treated 8 was moved into the reaction container 1 for n-layer film formation and set in the same procedure as the above film formation. 1 x
After evacuating to 10 ^-7 Torr or less, the heater built in the anode 3 is then energized to produce the object 8 to be treated.
The substrate was heated to 130 ° C. After the heating temperature by the heater was sufficiently stabilized, the raw material gases SiH ₄ , H ₂ and PH ₃ were introduced into the reaction vessel 1 through the gas supply pipe 6, and the pressure inside the reaction vessel 1 was controlled to 100 mTorr. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, high-frequency power is supplied from the high-frequency power source 4 to the discharge ladder-type electrode 2 through the impedance matching device 5, so that the discharge ladder-type electrode 2 and the object to be treated 8 are provided. A plasma 9 is generated between the n-type amorphous Si layer 32 and the i-type amorphous Si layer 32 of the object to be processed 8 having a thickness of 40 nm.
Layer 33 was formed into a film.

Then, on the n-type amorphous Si layer 33, the p-type microcrystalline Si layer 13, the i-type microcrystalline Si layer 14, the n-type microcrystalline Si layer 15, and the same method as in the first embodiment described above are used.
The second transparent electrode 16 made of indium oxide and the back electrode 17 made of Al were sequentially formed to manufacture the tandem solar cell shown in FIG.

Simulated sunlight (spectrum: AM1.5, irradiation intensity: 100 mW / cm ² , irradiation temperature: room temperature) was incident on the solar cell of Example 3 from the transparent insulating substrate side to evaluate the power generation characteristics. As a result, a large short circuit current value of 1.10 (relative value) was obtained as compared with the case where Comparative Example 1 was applied to the tandem.

(Embodiment 4) In this Embodiment 4, a manufacturing process of a solar cell having a tandem structure in which a pin structure is made of polycrystalline Si and light is incident from the transparent insulating substrate side is referred to FIG. And explain.

First, the first transparent electrode 1 made of tin oxide is formed on the transparent insulating substrate 11 made of soda-lime glass having light transmission.
Formed 2. Subsequently, a p-type amorphous Si layer 31, i is formed on the transparent electrode 12 by the same method as in the third embodiment.
-Type amorphous Si layer 32 and n-type amorphous Si
Layer 33 was sequentially formed. Subsequently, p-type is formed on the n-type amorphous Si layer 33 by the same method as in the second embodiment.
-Type polycrystalline Si layer 18, i-type polycrystalline Si layer 19, n-type polycrystalline Si layer 20, and second transparent electrode 1 made of indium oxide
6 and the back electrode 17 made of Al are sequentially formed, and FIG.
The tandem structure solar cell shown in was manufactured.

Simulated sunlight (spectrum: AM1.5, irradiation intensity: 100 mW / cm ² , irradiation temperature: room temperature) was incident on the solar cell of Example 4 from the transparent insulating substrate side to evaluate the power generation characteristics. As a result, a large short circuit current value was obtained as in Example 3.

(Embodiment 5) In this embodiment 5, light is incident from the second transparent electrode side and the nip structure is microcrystal S.
The manufacturing process of the solar cell made of i will be described with reference to FIG.

First, a back electrode 42 made of Al and a first transparent electrode 43 made of zinc oxide (ZnO) were formed on a transparent insulating substrate 41 made of soda-lime glass that transmits light.

Next, the plasma CV shown in FIG.
Reaction in which the transparent insulating substrate 41 having the transparent electrode 43 formed thereon is held as an object 8 to be processed in the anode 3 in the reaction container 1 for n-layer film formation in the apparatus D, and the object 8 is grounded through a lead. After connecting to the container 1, a vacuum pump (not shown) is operated to move the inside of the reaction container 1 through the exhaust pipe 7 to 1 × 1.
It was evacuated to below 0 ^-8 Torr. Subsequently, the heater incorporated in the anode 3 was energized to heat the substrate of the object 8 to be treated to a temperature of 160 ° C. After the heating temperature by the heater was sufficiently stabilized, the raw material gases SiH ₄ , H ₂ and PH ₃ were introduced into the reaction vessel 1 through the gas supply pipe 6, and the pressure inside the reaction vessel 1 was controlled to 700 mTorr. After the temperature and pressure inside the reaction vessel 1 are sufficiently stabilized,
By supplying high frequency power having a frequency of 100 MHz from the high frequency power source 4 to the discharging ladder electrode 2 through the impedance matching device 5, plasma 9 is generated between the discharging ladder electrode 2 and the object 8 to be treated, Treated product 8
N-type microcrystalline Si having a thickness of 30 nm on the first transparent electrode 43 of
Layer 44 was deposited.

Then, after forming the n-type microcrystalline Si layer 44,
The supply of the raw material gas was stopped and the inside of the reaction vessel 1 was evacuated. Subsequently, the object to be treated 8 is placed in the reaction container 1 for forming the i-layer.
Was moved and set in the same procedure as the above film formation. 1 x 10
After evacuating to ⁻⁷ Torr or less, the heater of the anode 3 was then energized to heat the substrate of the object to be treated 8 to 190 ° C. After the heating temperature by the heating heater is sufficiently stabilized, a mixed gas of SiH ₄ , SiH ₂ Cl ₂ and H ₂ , which is a raw material gas, is introduced into the reaction vessel 1 through the gas supply pipe 6, and then the reaction is performed. The pressure in the container 1 was controlled to 2.0 Torr. At this time, the amount of each gas is SiH ₄ : 3 to 7 sccm, SiH ₂ Cl ₂ (diluted with 1% hydrogen): 50 to 250 sccm, H ₂ : 100 to 25.
It was set to 0 sccm. Further, SiH ₂ Cl ₂ was in the range of 10 to 40% in flow rate with respect to the flow rate of all Si gas. After introducing the raw material gas and sufficiently stabilizing the temperature and pressure in the reaction vessel 1, a frequency of 100 MH is applied to the discharge ladder electrode 2 from the high frequency power source 4 through the impedance matching device 5.
Plasma is generated by supplying high-frequency power of 10 W for z and has a thickness of 150 on the n-type microcrystalline Si layer 44.
A 0 nm i-type microcrystalline Si layer 45 was formed. The i-type microcrystalline Si layer 45 contained chlorine at 6 × 10 ¹⁹ cm ⁻³ .

Then, after forming the i-type microcrystalline Si layer 45,
The supply of the raw material gas was stopped and the inside of the reaction vessel 1 was evacuated. Subsequently, the object to be treated 8 is placed in the reaction container 1 for p-layer film formation.
Was moved and set in the same procedure as the above film formation. 1 x 10
After evacuating to ⁻⁷ Torr or less, the heater of the anode 3 was then energized to heat the substrate of the object to be treated 8 to 160 ° C. After the heating temperature by the heater is sufficiently stabilized, raw material gases SiH ₄ , H ₂ and B ₂ H ₆ are introduced into the reaction vessel 1 through the gas supply pipe 6 to control the pressure in the reaction vessel 1 to 500 mTorr. did. After the temperature and pressure inside the reaction vessel 1 are sufficiently stabilized,
Impedance matching device 5 receives high frequency power from high frequency power source 4
Through the discharge ladder electrode 2 to generate a plasma 9 between the discharge ladder electrode 2 and the object 8 to be treated, and the i-type microcrystalline Si layer 4 of the object 8 to be treated.
A p-type microcrystalline Si layer 46 having a thickness of 30 nm was formed on the film 5. Then, the object to be processed was taken out from the reaction vessel 1 of the plasma CVD layer, and the second transparent electrode 47 made of indium oxide was formed on the p-type microcrystalline Si layer 46 to manufacture the solar cell shown in FIG.

As a result of examining the (110) orientation ratio of the i-type microcrystalline Si layer formed in Example 5, the same 29 as in Example 1 was obtained.
The value of was shown.

Moreover, simulated solar light (spectrum: AM1.5, irradiation intensity: 100 mW / c) was applied to the solar cell of Example 5.
m ^2, irradiation temperature: room temperature) is incident from the second transparent electrode side, to evaluate the power generation characteristics. As a result, a large short circuit current similar to that of Example 1 was obtained.

(Embodiment 6) In this embodiment 6, light is incident from the second transparent electrode side and the nip structure is polycrystalline S.
The manufacturing process of the solar cell made of i will be described with reference to FIG.

First, a back electrode 42 made of Al and a first transparent electrode 43 made of zinc oxide (ZnO) were formed on a transparent insulating substrate 41 made of soda-lime glass that transmits light.

Next, the plasma CV shown in FIG.
Reaction in which the transparent insulating substrate 41 having the transparent electrode 43 formed thereon is held as an object 8 to be processed in the anode 3 in the reaction container 1 for n-layer film formation in the apparatus D, and the object 8 is grounded through a lead. After connecting to the container 1, a vacuum pump (not shown) is operated to move the inside of the reaction container 1 through the exhaust pipe 7 to 1 × 1.
It was evacuated to below 0 ^-7 Torr. Subsequently, the heater incorporated in the anode 3 was energized to heat the substrate of the object 8 to be treated to a temperature of 180 ° C. After the heating temperature by the heater was sufficiently stabilized, the raw material gases SiH ₄ , H ₂ and PH ₃ were introduced into the reaction vessel 1 through the gas supply pipe 6, and the pressure inside the reaction vessel 1 was controlled to 700 mTorr. After the temperature and pressure inside the reaction vessel 1 are sufficiently stabilized,
By supplying high frequency power having a frequency of 100 MHz from the high frequency power source 4 to the discharging ladder electrode 2 through the impedance matching device 5, plasma 9 is generated between the discharging ladder electrode 2 and the object 8 to be treated, Treated product 8
N-type polycrystalline S having a thickness of 300 nm on the first transparent electrode 43 of
The i layer 48 was formed into a film.

Next, after forming the n-type polycrystalline Si layer 48,
The supply of the raw material gas was stopped and the inside of the reaction vessel 1 was evacuated. Subsequently, the object to be treated 8 is placed in the reaction container 1 for forming the i-layer.
Was moved and set in the same manner as the film formation of the n-type microcrystalline Si layer 13. After evacuation to 1 × 10 ⁻⁷ Torr or less, the heater of the anode 3 was then energized to heat the substrate of the object 8 to be heated to 210 ° C. After the heating temperature by the heater is sufficiently stabilized, a mixed gas of SiH ₄ , SiH ₂ Cl ₂ and H ₂ , which is a raw material gas, is introduced into the reaction vessel 1 through the gas supply pipe 6, and then the pressure in the reaction vessel 1 is changed. Was controlled to 1.0 Torr. At this time, the amount of each gas is SiH ₄ : 5 to 10 sccm, SiH ₂ Cl ₂ (1
% Hydrogen dilution): 100 to 200 sccm, H ₂ : 100
˜200 sccm. SiH ₂ Cl ₂ is the total Si
The flow rate was in the range of 10 to 30% with respect to the gas flow rate. After introducing the raw material gas and sufficiently stabilizing the temperature and pressure in the reaction vessel 1, a frequency 10 is applied to the discharge ladder electrode 2 from the high frequency power source 4 through the impedance matching device 5.
Plasma is generated by supplying high-frequency power of 0 MHz and 70 mW / cm ^{2 to} the n-type polycrystalline Si layer 48.
An i-type polycrystalline Si layer 49 having a thickness of 1500 nm was formed on the film. The i-type polycrystalline Si layer 49 contains 4 × 10 ¹⁹ c of chlorine.
m ^{-3 was} contained.

Then, after forming the i-type polycrystalline Si layer 49,
The supply of the raw material gas was stopped and the inside of the reaction vessel 1 was evacuated. Subsequently, the object to be treated 8 is placed in the reaction container 1 for p-layer film formation.
Was moved and set in the same procedure as the above film formation. 1 x 10
After evacuation to ^-7 Torr or less, the heater of the anode 3 was then energized to heat the substrate of the object 8 to be processed to 180 ° C. After the heating temperature by the heater is sufficiently stabilized, the raw material gases SiH ₄ , H ₂ and B ₂ H ₆ are introduced into the reaction vessel 1 through the gas supply pipe 6 to control the pressure in the reaction vessel 1 to 700 mTorr. did. After the temperature and pressure inside the reaction vessel 1 are sufficiently stabilized,
Impedance matching device 5 receives high frequency power from high frequency power source 4
Through the discharge ladder electrode 2 to generate a plasma 9 between the discharge ladder electrode 2 and the object 8 to be processed, and the i-type polycrystalline Si layer 4 of the object 8 to be processed.
A p-type polycrystalline Si layer 50 having a thickness of 30 nm was formed on the substrate 9. Then, the object to be processed was taken out of the reaction vessel 1 having the plasma CVD layer, and the second transparent electrode 47 made of indium oxide was formed on the p-type polycrystalline Si layer 50 to manufacture the solar cell shown in FIG.

As a result of examining the (110) orientation ratio of the i-type polycrystalline Si layer formed in Example 6, the same 29 as in Example 1 was obtained.
The value of was shown.

In addition, simulated solar light (spectrum: AM1.5, irradiation intensity: 100 mW / c) was applied to the solar cell of Example 6.
m ^2, irradiation temperature: room temperature) is incident from the second transparent electrode side, to evaluate the power generation characteristics. As a result, a large short circuit current similar to that of Example 1 was obtained.

(Embodiment 7) In this embodiment 7, light is incident from the second transparent electrode side, and the nip structure is microcrystal S.
A manufacturing process of a solar cell made of i and having a tandem structure will be described with reference to FIG.

First, a back electrode 42 made of Al and a first transparent electrode 43 made of tin oxide were formed on a transparent insulating substrate 41 made of soda-lime glass having light transmission. Then, on the second transparent electrode 43, an n-type microcrystalline Si layer 43, an i-type microcrystalline Si layer 44, p is formed by the same method as in the fifth embodiment.
The type microcrystalline Si layer 45 was sequentially formed. Subsequently, an n-type amorphous Si layer 51 and an i-type amorphous Si layer 52 are formed on the p-type microcrystalline Si layer 45 by the same method as in the third embodiment.
Then, the p-type amorphous Si layer 53 was sequentially formed, and the second transparent electrode 47 made of indium oxide was further formed to manufacture the tandem solar cell shown in FIG.

Simulated sunlight (spectrum: AM1.5, irradiation intensity: 100 mW / cm ² , irradiation temperature: room temperature) was incident on the solar cell of Example 7 from the side of the second transparent electrode, and the power generation characteristics were evaluated. As a result, a large short circuit current value of 1.10 (relative value) was obtained as compared with the case where Comparative Example 1 was applied to the tandem.

(Embodiment 8) In this embodiment 8, a manufacturing process of a solar cell having a tandem structure in which the nip structure is made of polycrystalline Si and light is incident from the transparent insulating substrate side is referred to FIG. And explain.

First, a back electrode 42 made of Al and a first transparent electrode 43 made of tin oxide were formed on a transparent insulating substrate 41 made of soda-lime glass having light transmission. Then, on the second transparent electrode 43, an n-type polycrystalline Si layer 48, an i-type polycrystalline Si layer 49, p are formed by the same method as in the sixth embodiment.
The type polycrystalline Si layer 50 was sequentially formed. Subsequently, an n-type amorphous Si layer 51 and an i-type amorphous Si layer 52 are formed on the p-type polycrystalline Si layer 50 by the same method as in the third embodiment.
Then, the p-type amorphous Si layer 53 was sequentially formed, and the second transparent electrode 47 made of indium oxide was further formed to manufacture the tandem solar cell shown in FIG.

Simulated sunlight (spectrum: AM1.5, irradiation intensity: 100 mW / cm ² , irradiation temperature: room temperature) was incident on the solar cell of Example 8 from the side of the second transparent electrode, and the power generation characteristics were evaluated. As a result, a large short circuit current value was obtained as in Example 7.

[0110]

As described in detail above, according to the present invention, the first transparent electrode, the pin structure or the ni structure is formed on the transparent insulating substrate.
In manufacturing a solar cell having a structure in which a microcrystalline silicon layer or a polycrystalline silicon layer having a p structure, a second transparent electrode and a back electrode are sequentially formed and light is incident from the transparent insulating substrate side, at least an i-type By forming a crystalline silicon layer or a polycrystalline silicon layer at a lower temperature and at a lower cost than conventional techniques, the light transmittance of the first transparent electrode is reduced, and the electrical characteristics at the pi junction interface or the ni junction interface are reduced. And a method for manufacturing a solar cell in which the i-type microcrystalline silicon layer or the polycrystalline silicon layer can be (110) preferentially oriented without further deterioration and the power generation characteristics such as short circuit current are improved. Can be provided.

Further, according to the present invention, a back electrode, a first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, and a second transparent electrode are sequentially formed on a transparent insulating substrate, In manufacturing a solar cell having a structure in which light is incident from the second transparent electrode side, at least an i-type microcrystalline silicon layer or a polycrystalline silicon layer is formed at a lower temperature and at a lower cost as compared with the conventional technique. The (110) preferential orientation of the i-type microcrystalline silicon layer or the polycrystalline silicon layer without deteriorating the light transmittance of the first transparent electrode and deteriorating the electrical characteristics at the pi junction interface or the ni junction interface. Thus, it is possible to provide a method for manufacturing a solar cell having improved power generation characteristics such as short-circuit current.

Further, according to the present invention, a pin structure microcrystalline silicon layer or a polycrystalline silicon layer including an i-type microcrystalline silicon layer or a polycrystalline silicon layer exhibiting (110) preferential orientation is provided, and a short circuit current It is possible to provide a solar cell having improved power generation characteristics as described above.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a plasma CVD apparatus that manufactures a solar cell of the present invention.

FIG. 2 is a plan view of a discharge ladder electrode.

FIG. 3 is a cross-sectional view showing the structure of the solar cell according to the first embodiment of the present invention.

FIG. 4 is a characteristic diagram showing the short-circuit current of the solar cells in Example 1 and Comparative Example 1 of the present invention.

FIG. 5 is a cross-sectional view showing the structure of the solar cell according to the second embodiment of the present invention.

FIG. 6 is a sectional view showing a structure of a solar cell according to a third embodiment of the present invention.

FIG. 7 is a sectional view showing a structure of a solar cell according to a fourth embodiment of the present invention.

FIG. 8 is a sectional view showing a structure of a solar cell according to a fifth embodiment of the present invention.

FIG. 9 is a sectional view showing the structure of a solar cell according to Example 6 of the present invention.

FIG. 10 is a sectional view showing the structure of a solar cell according to Example 7 of the present invention.

FIG. 11 is a cross-sectional view showing the structure of the solar cell according to Example 8 of the present invention.

FIG. 12 is a cross-sectional view showing the structure of a conventional solar cell.

FIG. 13 is a cross-sectional view for explaining problems in a conventional solar cell manufacturing process.

FIG. 14 is a cross-sectional view for explaining another problem in the conventional solar cell manufacturing process.

[Explanation of symbols]

1 ... Reaction vessel, 2 ... Discharge ladder electrode, 3 ... Anode, 4 ... High frequency power supply, 5 ... Matching device, 6 ... Gas supply pipe, 7 ... Exhaust pipe, 8 ... Object to be processed, 9 ... plasma, 11, 41 ... Transparent insulating substrate, 12, 42 ... First transparent electrode, 13, 46 ... p-type microcrystalline Si layer, 14, 45 ... i-type microcrystalline Si layer, 15, 44 ... n-type microcrystalline Si layer, 16, 47 ... Second transparent electrode, 17, 42 ... Back electrode, 18, 50 ... p-type polycrystalline Si layer, 19, 49 ... i-type polycrystalline Si layer, 20, 48 ... n-type polycrystalline Si layer, 31, 53 ... p-type amorphous Si layer, 32, 52 ... i-type amorphous Si layer, 33, 51 ... N-type amorphous Si layer.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shoji Morita             1-8 Koura, Kanazawa-ku, Yokohama-shi, Kanagawa               Mitsubishi Heavy Industries, Ltd. Basic Technology Research Center F-term (reference) 4K030 AA03 AA06 BB03 BB04 CA06                       CA12 FA03 JA05 JA09 JA10                       JA18 KA24 LA16                 5F045 AA08 AB03 AC01 AC03 AC05                       AD05 AD06 AD07 AE19 AE21                       AE23 AF07 BB07 CA13 DA59                       DP09 EH04 EH09                 5F051 AA03 AA04 BA18 CA03 CA07                       CA08 CA16 CA23 DA04 FA03                       FA04 GA03

Claims (16)

[Claims] 1. A first transparent electrode and p on a transparent insulating substrate.
In manufacturing a solar cell in which a microcrystalline silicon layer or a polycrystalline silicon layer having an in structure or a nip structure, a second transparent electrode, and a back electrode are sequentially formed, and light is incident from the transparent insulating substrate side, A reaction vessel, a gas supply means for supplying a raw material gas to the reaction vessel, a discharge means for discharging a gas in the reaction vessel, a discharge ladder electrode arranged in the reaction vessel, and A power source for supplying glow discharge generation power to the discharge ladder electrode, and a support electrode that is arranged in the reaction vessel in parallel with the discharge ladder electrode and is spaced apart from the discharge ladder electrode, and includes a heater for heating. Using a CVD apparatus, at least an i-type microcrystalline silicon layer or polycrystalline silicon layer among the microcrystalline silicon layer or polycrystalline silicon layer having the pin structure or the nip structure , The CVD
An object to be processed having the transparent insulating substrate is supported on a supporting electrode of the apparatus and heated to produce SiH ₄ , SiH ₂ Cl ₂ , and SiH.
A mixed gas of at least one silicon chlorinated compound gas selected from Cl ₃ and SiCl ₄ and H ₂ is supplied as the raw material gas from the gas supply means into the reaction vessel, and a frequency is supplied from the power supply to a ladder-type electrode. A method for producing a solar cell, which comprises forming a film by supplying a high frequency power for glow discharge generation of 60 MHz or more to cause glow discharge in the reaction vessel to generate plasma. 2. The arrangement of p, i, n between the first transparent electrode and the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure is the microcrystalline silicon layer or the polycrystalline silicon layer. The method for manufacturing a solar cell according to claim 1, wherein an amorphous silicon layer having a pin structure or a nip structure similar to the layer is arranged. 3. A back electrode, a first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, and a second transparent electrode are sequentially formed on a transparent insulating substrate, When manufacturing a solar cell in which light is incident from the second transparent electrode side, a reaction container, gas supply means for supplying a raw material gas to this reaction container, and discharge means for discharging gas in the reaction container. A discharge ladder electrode disposed in the reaction vessel, a power source for supplying high-frequency power for glow discharge generation to the discharge ladder electrode, and a discharge ladder electrode separated from the reaction vessel Of the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure, using a CVD apparatus provided with a supporting electrode having a heater for heating. Kutomo i-type microcrystalline silicon layer or a polycrystalline silicon layer, the CVD
An object to be processed having the transparent insulating substrate is supported on a supporting electrode of the apparatus and heated to produce SiH ₄ , SiH ₂ Cl ₂ , and SiH.
A mixed gas of at least one silicon chlorinated compound gas selected from Cl ₃ and SiCl ₄ and H ₂ is supplied as the raw material gas from the gas supply means into the reaction vessel, and a frequency is supplied from the power supply to a ladder-type electrode. A method for producing a solar cell, wherein a film is formed by supplying glow discharge generation power of 60 MHz or more to cause glow discharge in the reaction vessel to generate plasma. 4. A microcrystalline silicon layer or polycrystalline silicon layer having a pin structure or a nip structure and a p, i, or n arrangement between the microcrystalline silicon layer or polycrystalline silicon layer and the second transparent electrode. The method for manufacturing a solar cell according to claim 3, wherein an amorphous silicon layer having a pin structure or a nip structure similar to the layer is arranged. 5. The film forming of at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer is heated to a temperature of 120 to 300 ° C. by a heater of the supporting electrode. A method for manufacturing the solar cell described. 6. The film forming of at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer is heated to a temperature of 160 to 210 ° C. by a heater of the supporting electrode. A method for manufacturing the solar cell described. 7. The silicon chlorinated compound gas is supplied to the reaction vessel at a flow rate ratio of 1 to 80% with respect to the total flow rate of the SiH ₄ and the silicon chlorinated compound gas. The method for manufacturing a solar cell according to claim 1 or 3, characterized in that: 8. The silicon chlorinated compound gas is supplied to the reaction vessel at a flow rate ratio of 10 to 40% with respect to the total flow rate of the SiH ₄ and the silicon chlorinated compound gas. The method for manufacturing a solar cell according to claim 1 or 3, characterized in that: 9. The film formation of at least an i-type microcrystalline silicon layer or a polycrystalline silicon layer, wherein the pressure in the reaction vessel is set in the range of 0.5 to 10 Torr. Manufacturing method of solar cell. 10. The film formation of at least an i-type microcrystalline silicon layer or a polycrystalline silicon layer, wherein the pressure in the reaction vessel is set in the range of 0.5 to 3 Torr. Manufacturing method of solar cell. 11. A first transparent electrode on a transparent insulating substrate,
A solar cell in which a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, a second transparent electrode, and a back electrode are sequentially formed, and light is incident from the transparent insulating substrate side. Or, of the microcrystalline silicon layer or the polycrystalline silicon layer having the nip structure, at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer contains 1 × chlorine.
A solar cell containing 10 ¹⁸ cm ⁻³ to 8 × 10 ²⁰ cm ⁻³ . 12. The chlorine of 2 × 10 ¹⁹ cm ⁻³ at least in the i-type microcrystalline silicon layer or polycrystalline silicon layer.
The content of 4 × 10 ²⁰ cm ^{−3 is} contained.
1. The solar cell according to 1. 13. The first transparent electrode and the pin
Amorphous silicon layer having a pin structure or a nip structure in which the arrangement of p, i, n is similar to that of the microcrystalline silicon layer or the polycrystalline silicon layer between the microcrystalline silicon layer or the polycrystalline silicon layer having the structure or the nip structure The solar cell according to claim 11, wherein the solar cell is arranged. 14. A back electrode and a first electrode on a transparent insulating substrate.
A solar cell in which a transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, and a second transparent electrode are sequentially formed, and light is incident from the second transparent electrode side. Or, of the microcrystalline silicon layer or the polycrystalline silicon layer having the nip structure, at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer contains 1 × chlorine.
A solar cell containing 10 ¹⁸ cm ⁻³ to 8 × 10 ²⁰ cm ⁻³ . 15. At least the i-type microcrystalline silicon layer or polycrystalline silicon layer contains chlorine at 2 × 10 ¹⁹ cm ^−3.
The content of 4 × 10 ²⁰ cm ^{−3 is} contained.
4. The solar cell according to 4. 16. The microcrystalline silicon layer or polycrystalline silicon having a p, i, n arrangement between the microcrystalline silicon layer or polycrystalline silicon layer having the pin structure or the nip structure and the second transparent electrode. The solar cell according to claim 14, wherein an amorphous silicon layer having a pin structure or a nip structure similar to the layer is arranged.