JPH0273671A - Manufacture of photoelectric transfer element - Google Patents

Abstract

PURPOSE:To manufacture a photoelectric transfer element wherein output characteristics are improved by forming the photoelectric transfer layer of the photoelectric transfer element using single crystal semiconductor powder, by p-n junction which arises in powder by alloying with a rear electrode. CONSTITUTION:An Al film is stacked as a rear electrode 4 on a diffusion preventive layer 5 by, for example, deposition. Separately, n-type single powder 2 is mixed with insulating material 7 and is dissolved in organic substance to make paste, and this paste is printed onto the electrode 4. Next, it is inserted into a heating furnace together with a substrate and is heated in inert gas and forming gas. First, it is heated at a specific temperature so as to evaporate the organic substance and further it is heated so as to generate eutectic solution of Al of the electrode 4 with Si to form Al-Si alloy between Si powder 8 and the electrode 4. When the temperature is further raised, insulating substance 7 fuses and covers the Al-Si alloy. Thereafter, when the temperature is lowered gradually, the fused part between the powder 8 and the alloy layer diffuses with Al as dopant into Si, whereby a p-type Si layer 6 is formed at the time of solidification.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a photoelectric conversion element using single crystal semiconductor powder.

[Conventional technology]

In charge conversion elements using semiconductors, various materials are used for the semiconductors. When using a thin film semiconductor layer,
Amorphous 31 is often used. However, when using amorphous Sl, the film thickness is 11
tm, but since it is formed using a vacuum device, the A11L size of the device itself is large, which increases the cost.
There is a big problem of photodeterioration in terms of II properties. When using single crystal 51 as a semiconductor, there is no problem in terms of stability and conversion efficiency, but if the Sl used as material is 200
There are problems in that it is thick and expensive.

Therefore, there is a need for a charge conversion element that can reduce costs in terms of materials and processes, and in response to this, photoelectric conversion elements using single crystal semiconductor powder are being considered. This structure and manufacturing method will be explained with reference to FIG. 2. First, a Mo layer, for example, is formed as the diffusion prevention layer 5 on the substrate 1,
Next, for example, 11 is formed as the back surface mold 8i4.

A paste formed by mixing p-type single-crystal St powder 8 having crystal grains of about Pk25n with insulating material 7 and dissolving it in an organic substance is printed on it. A glass raw material is used as the edge material 7, and polyvinyl alcohol is used as the organic substance. Next, the substrate is charged into a heating furnace,
Heat in inert gas and forming gas. 200
The organic substance evaporates at about ℃. When heated further to about 600℃, eutectic fusion of M and St of pole 4 starts on the back side, and Aj-5l is formed between Sl powder 8 and 1Pit 4.
of molten alloy is formed.

When the temperature is further increased, the insulating material 7 melts and covers the top of the MS1 alloy stone. Thereafter, when the temperature is gradually lowered, the deposited layer from the kl-3i molten alloy of the A7 electrode 4 and the Si powder 8 becomes p'-type Si9, and electrical contact with the back electrode 4 is formed. Next, the surfaces of the crystal grains are polished, and an extremely thin A7 thin film is formed thereon as the light incident side electrode 10. This TLff+ has the purpose of forming a Schottky junction with the Sl powder 8 as well as being a counter electrode with the back electrode 4 .

[Problem to be Solved by the Invention] Such light; in the conversion element barrel manufacturing, a diode is formed by forming a Schottky junction, and in order to enable photoelectric conversion, Si powder is used as the electrode 10 on the light incident side. body 8
A metal that can form a Schottky junction with the metal must be used, which has the disadvantage of narrowing the selection range of electrode materials. In addition, since metal is used as the q-ring, the thickness of the IT electrode must be at least several tens of layers in order to make good electrical contact, which reduces the light transmittance and increases the reflectance. However, there was a problem in that the substantial amount of incident light entering the charge conversion layer formed on the Si powder 8 was reduced, and the output characteristics were also lowered.

An object of the present invention is to provide a method for manufacturing a low-cost photoelectric conversion element with high output characteristics by increasing the amount of light incident on the semiconductor powder forming the charge conversion layer from the light incident side electrode.

[Means to solve the problem]

In order to solve the above problems, the present invention includes a step of arranging single crystal semiconductor powder of a first conductivity type densely on the same plane, and a second R-shape carved into the semiconductor powder on one side of the surface. A process of contacting an 'ifl film of a conductive material containing doping impurities for the purpose of heating, and heating to alloy the semiconductor powder and the conductive material, and then cooling to form a region of the second conductivity type in a part of the semiconductor powder. and a step of covering the other side of the semiconductor powder with a transparent electrode.

[Effect]

In the above method, the conductive material containing the toping impurity is alloyed with the semiconductor powder and upon cooling creates a p-n junction that forms a charge conversion layer within the semiconductor powder;
Scratch one of the photoelectric transducer tags. The transparent electrode covering the other side of the semiconductor powder has higher transmittance than the electrode that also forms the Schottky junction.

Since the reflectance can be made low, the amount of light incident on the conversion layer is increased, and the output characteristics of the device are improved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1 (al to (al) in which parts common to those in FIG. Examples include alumina silicate glass and quartz glass.

A diffusion prevention layer 5 is formed on an insulating substrate 1 made of ceramic such as alumina to prevent impurities from diffusing from the substrate.
(Figure a). Prevention of spread I! ! 5 is a silicon dioxide film,
g! The silicon oxide film is Mo, which is a high melting point metal.

An A7 film is laminated as the back electrode 4 on the zero-order diffusion prevention J55 using an N1 film or the like, for example, by vapor deposition.
(Figure b), separately, an n-type single crystal S1 powder 2, which is crystal grains with a grain size of about 25 nm, is mixed with an insulating material 7, dissolved in an organic substance to create a paste, and this paste is applied to the M film 4.
(Figure c) Glass raw material is used as the insulating material 7, and polyvinyl alcohol is used as the organic substance.Next, the substrate is charged into a heating furnace and heated in an inert gas and forming gas. Heat. Organic substances first evaporate by heating to about 200℃, then further heating to 600℃
When moving back and forth, eutectic fusion between M and St of the back electrode 4 begins,
AN-81 alloy is formed between the Sl powder 8 and the electrode 4.

When the temperature is further increased, the m-green substance 7 melts and covers the M-si gold alloy. This is the light incident side electrode 3 and the back side electrode 4.
When the temperature is then gradually lowered, M diffuses into the Si as a dopant in the melted zone between the Si powder 8 and the alloy layer, resulting in p-type 5ill 6 during solidification. is formed (figure d), thus n-type St
This means that a pn junction is formed in the powder 2. After that, the surface of the crystal grains is polished, and then ITO, which is a translucent conductive material, is polished.
or 5nOtl film. When ITO, 5nOt, or the like is used, the reflectance can be controlled by the thin film. For example, by forming a thin film as thick as about 700 deer, the reflectance can be minimized.

In another embodiment of the invention, the substrate is not insulating but a refractory metal, such as 0M. A metal plate such as 1Ni may also be used; in this case, diffusion prevention J! 5 may not be formed.Furthermore, the characteristics of the Ohma battery of the present invention were evaluated. In the conventional method, A7B is used as the light entrance window.
It is formed to a human thickness, and the present invention uses IT as a light entrance window
O was formed to a thickness of about 700 people. As a result, the short-circuit photocurrent output was 12 mA/cd in the conventional method, but it was increased to 15 m^/d in the present invention, and it was possible to improve the conversion efficiency.

In the above embodiments, n-type S1 powder was used as the single-crystal semiconductor powder, but p-type powder may also be used, and in that case, a 5n-3b alloy or the like may be used for the backside electrical bridge.

〔Effect of the invention〕

According to the present invention, the photoelectric conversion layer of a photoelectric conversion element using a single crystal semiconductor powder is also formed in the powder by alloying with the back surface electrode, instead of by the conventional shishit-key bonding with the light incident side electrode. Since it is formed by pnf1 combination, it is possible to use a transparent electric bridge that is effective in terms of transmittance and reflectance as the light incident side electrode, and it is possible to use a transparent electric bridge that is effective in terms of transmittance and reflectance. It has become possible to manufacture low-cost photoelectric conversion elements with improved output characteristics.

[Brief explanation of the drawing]

FIG. 1 is a sectional view sequentially showing the manufacturing process of a photoelectric conversion device according to an embodiment of the present invention, and FIG. 2121 is a plan view of a conventional optical g1 variable variable device using single crystal semiconductor powder. 1: Insulating substrate, 2: N-type Sl powder, 3: Light incident side electrode, 4: S-plane electrode, 5: Anti-diffusion layer, 6: P-type Sl1g
, 7: Insulating material. Representative Patent Attorney Yoshii YamaguchiFigure 2Figure 1

Claims (1)

[Claims] 1) A process of densely arranging single crystal semiconductor powder of the first conductivity type on the same plane, and placing the semiconductor powder on one side of the plane,
A process of contacting a thin film of conductive material containing doping impurities for a second conductivity type, and heating to alloy the semiconductor powder and the conductive material, and then cooling to form a second conductivity in a part of the semiconductor powder. 1. A method for manufacturing a photoelectric conversion element, comprising a step of forming a shaped region and a step of covering the other side of the semiconductor powder with a light-transmitting electrode.