JPS5853865A - Method for manufacturing amorphous silicon solar cells - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention relates to amorphous silicon (hereinafter referred to as a-5t).
The present invention relates to a method for manufacturing a solar cell using i.

As disclosed in U.S. Pat. No. 4,064,521, a general method for manufacturing an α-5i solar cell and its structure, the α-5i solar cell is manufactured by glue discharge decomposition of siL to form a semiconductor junction.

Conventionally, methods for generating green discharge plasma include:
Spring coupling method using parallel plate electrodes and coiled electrodes
The induction metallization method is mainly used.

Additionally, the substrate temperature during production of g-5i solar cells was conventionally 250°C.
~350°C, and the thickness of the G-5 layer of a 5g-5i solar cell is approximately 5007%, or pya is approximately took.

The 1st layer is about 50004% and the electric layer is about 300%! and a
- Concentration of SiH, gas for 5-layer lamination #'i - When i is used for the purpose of making microcrystals, etc., it is approximately 1051 or 10
0- gas was often used.

The open-circuit voltage of single-a-5i solar cell elements obtained by these conventional methods was about 85011 V at most, and the photoelectric conversion efficiency was about 6% at most.

The present invention attempts to improve these problems by using a method for manufacturing α-5i solar cells that is different from conventional methods.

The feature of the present invention is that ring-shaped electrodes are capacitively coupled, and a-Si
A laminated substrate is placed apart from the ring-shaped electrode, and glow discharge plasma is generated to laminate 1-5i.

In this case, Si in the plasma reactor diluted with other gases
B. The features of the present invention include keeping the concentration below 5 arcs and keeping the substrate temperature below 200°C, which is lower than before.0 The present invention, based on the above conditions, The objective is to obtain a relatively thin solar cell with high voltage and high conversion efficiency.

The present invention will be explained below using the drawings.

As shown in FIG. 1, ring-shaped electrodes, for example, two ring-shaped electrodes 1, are capacitively coupled, glue discharge plasma is generated, and g-5i is laminated. In this case, the ring-shaped electrodes and the α-5i laminated substrate 2 at an appropriate distance apart.

□ Uniform plasma with good stability was obtained by using a rice seed electrode. This method uses parallel plate electrodes.
Compared to the capacitive coupling method, this method has advantages such as less impact on the a-5i film by plasma and the ease of keeping the plasma reaction system clean.

SiB, then diluted with a diluent gas, e.g. hydrogen,
The concentration shall be 5% or less.

This technology improves the charge conversion efficiency of the a-5i solar cell and at the same time greatly reduces the consumption of expensive Si tile gas. The temperature of the substrate 2 is set to 200° C. or less, which is lower than the conventional value.

As a result 1, as shown in Fig. 2, a particularly high open-circuit voltage, that is, a very high open-circuit voltage Voc (May) = 945 w, which could not be obtained conventionally for a 1-A-5i solar cell element, was obtained.
hV was obtained. Incidentally, as is clear from FIG. 2, when the substrate temperature was set to 250° C. or higher, only a low open circuit voltage comparable to the conventional one could be obtained.

The horizontal axis in FIG. 2 indicates the substrate temperature 'II (C), and the vertical axis indicates the open circuit voltage Voc (mV).

In addition, the photoelectric conversion efficiency was greatly improved, and as shown in FIG. 3, η-6.26% was obtained at illuminance AM-1.

In FIG. 3, the horizontal axis represents voltage and the vertical axis represents current. In this case, the open circuit voltage is 0・q+gV, and the short circuit current is It-43wh.
The A/cd fill factor H0,597-1 conversion efficiency was 6.26%. The total thickness of the og-5i layer was approximately 25
00i, which was a little thinner than the conventional one.

An example of a solar cell structure according to the present invention is an indium tin oxide film (ITO film = (InwOa)) on glass.
+-z(Snog>at-x=~5% e~1
00 Ω/cd), the P-type layer, each layer, and the outer layer were sequentially laminated, and finally, AI was vapor-deposited as an electrode (hereinafter, this solar cell structure will be referred to as ITO/P-*-n/A).
(referred to as I).

Embodiment I of the present invention will be described below.

As mentioned above, FIG. 1 shows one embodiment of the apparatus of the present invention. Blaz! As the high frequency for generation, 8MH5, which is one of the frequencies that matched well with the device, was used.

A matching box 3 was placed between the high frequency power source and the electrodes to perform matching.

A quartz cylinder 4 of 15Qssφ is used for the plasma generation furnace.The 0 electrode connects the inner wire of a high frequency coaxial cable capacitively coupled two ring-shaped electrodes 1 to the upper electrode on the side far from the substrate, and the outer lIl! Connected to the electrode at the bottom of the tube. Note that the outside S is not connected to the chassis of the high frequency power supply and is not grounded. Be careful, as the way plasma is generated will change depending on whether or not it is grounded. The ring-shaped electrode 1 has a width of 2. J,,1III, made of copper plate 0.4 mm thick. Further, the interval between the ring-shaped electrodes 1 was set to 30 cm.

Of the two ring-shaped electrodes 1, the distance between the lower end of the lower electrode and the a-Si lamination substrate 2 placed on the heated susceptor 5 was 5 square meters. The two ring-shaped electrodes I11'
11 is wound around the outer wall of the quartz cylinder 4 of the plasma generating furnace.

The substrate 2 contained ITO-coated goblet glass or SnQ-coated goose glass. Both have a resistance value of about I00Ω/cd. Si
& is diluted with Hl, and its concentration is rumored to be 1 in 4 widths by volume ◇ As dopants, \PHs is used for the N type, and B snow H is used for the P type.
・ was used.

The gas pressure in the plasma furnace when stacking a-5n layers is about i Torr (
Torr). The optimal distance between the lower electrode and the substrate changed depending on the gas pressure, and the higher the gas pressure, the shorter the distance. The substrate temperature when stacking α-5i is #! Lamination was carried out at 100 to 200°C as shown in Figure 2, and usually at 150°C.

The structure of the α-5i solar cell produced under the above conditions is I
TO(S)/P-1-nlAl type, P layer is about lε
Each OJS layer is approximately 2000.4. The number of layers was approximately 1501.

As for the characteristics of the g-5ii:@ battery, the open circuit voltage Vec was extremely high compared to the values obtained conventionally, and a high photoelectric conversion efficiency of 41F-6.26% was obtained for iM-1.

As shown in Figure 4, supporting this large open-circuit voltage, the optical forbidden band width of g-5i is also O,1
The thickness of 0n-5i, which was larger than gF, was about 2so.
The thickness is about half that of the conventional one, and the concentration of expensive SiL gas can be saved by keeping it below 5 meters.〇The substrate temperature when stacking α-5i is below 200℃. This is also a favorable result from the point of view of energy consumption.

From the above results, the present invention is extremely convenient and useful for producing a low-cost A-5i solar cell with high voltage, high conversion efficiency, and high conversion efficiency.

Note that it is clear that the present invention also includes arranging a plurality of the plasma generation electrodes used here in the same reactor and producing a large number of 6-5i solar cells at the same time.

[Brief explanation of drawings]

#1#vlJFi Figure 112, which is an explanatory diagram of the configuration of the device used in the method of the present invention, is a graph showing the dependence of the open circuit voltage on the substrate temperature, where the horizontal axis is the substrate temperature TS (0, and the vertical axis is the open circuit voltage Vo).
c (tyh). Fig. 113 is a current-voltage characteristic diagram of the g-5i solar cell, where the horizontal axis shows the voltage (c) and the vertical axis shows the current (mn/cd). Fig. 4 shows the g-5i solar cell. It is an explanatory diagram of the substrate temperature dependence of the optical forbidden width of 5K, where the horizontal axis shows the substrate temperature T # (Q, and the vertical axis shows the optical forbidden width (-r). 1... Ring-shaped electrode , 2... a -Si laminated substrate, 3... matching box, 4... quartz cylinder. Applicant: Komatsu Electronic Metals Co., Ltd. Komatsu Manufacturing Co., Ltd. Representative Patent Attorney: Masaaki Yonehara Patent Attorney Shi Hamamoto Figure 1 @ Figure 3 IjJE (1/1

Claims (1)

[Claims] (+) α-5i using Si tiles and glue discharge
In a method of manufacturing an amorphous silicon solar cell by laminating films, one ring-shaped electrode l is capacitively coupled, a g-5 layer laminated substrate 2 is placed apart from the ring-shaped electrode I, and this a
- A method for manufacturing an amorphous silicon solar cell, characterized in that α-5i is laminated on a five-layer laminated substrate 2. (2) A method for manufacturing an amorphous silicon solar cell of 11N(+) according to the claims, which uses two ring-shaped electrodes 1. (3) A patent claim that the temperature of the a-Si laminated substrate 2 is 200° C. or less (method for making an amorphous silicon solar cell) (4) A patent that the concentration of SiH is 5 or less A method for producing an amorphous silicon solar cell according to claim 1c(+).