JPS60218882A - Optical power generating element - Google Patents

Abstract

PURPOSE:To simplify working to a large extent and to implement a low cost, by forming an amorphous silicon solar battery and a protecting diode on the same substrate. CONSTITUTION:A lower electrode 1 for an element and a lower electrode 2 for a protecting diode are separately formed on an insulating substrate 6. An amorphous silicon P-I-N element for the element and the protecting diode, in which a P-type doping layer is arranged on a light input surface, or an N-I-P element 3, which is constituted in the reverse order, are formed. A reflection preventing film 7 is formed on the P-I-N element 3a for the element. Then an upper electrode 4 for the element is formed so that a part of the electrode is connected to the lower electrode 2 for the protecting diode. An upper electrode 5 for the protecting diode is formed so that a part of the electrode 5 is connected to the lower electrode 1 for the electrode. Thus the amorphous silicon solar battery with the protecting diode can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a photovoltaic device, and particularly to the practical application of an amorphous silicon solar cell for power use.

[Prior art]

In general, an amorphous silicon solar cell has a lower breakdown voltage in the reverse direction than the other, so when several elements are assembled into one module, if one part is in the shadow, other elements may Power is applied in the opposite direction and the shaded elements are destroyed, so a protection diode is required, but in the past, this protection diode was attached to the outside of the board.

A conventional device of this type is shown in FIG. In the module 10 shown in FIG. 1, one protection diode 30 is provided for one element (amorphous silicon solar cell) 20.
is attached to the back side of the module 10 by a lead wire from the element 20 with its polarity reversed, thereby obtaining an IV characteristic as shown in FIG. Therefore, even when a voltage is applied to the element 20 in the reverse direction, current flows through the protection diode 30, thereby solving the problem of reverse breakdown voltage. In FIG. 2, D indicates the forward characteristic of the protection diode, and S indicates the dark period characteristic of the solar cell.

However, as with this conventional device, it takes a lot of time to extend the lead wires from the element and attach the protective diodes to the back side of the module, which results in poor workability when assembling the module. There were drawbacks.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and by forming a protection diode using amorphous silicon on the same substrate as the element, assembly of the module can be facilitated. The purpose is to provide a photovoltaic device that can .

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

In the present invention, instead of the conventional external protection diode, a protection diode is formed using amorphous silicon on the same substrate as the element (amorphous silicon solar cell), and FIG. 3(a) shows the first implementation thereof. This is an example. FIG. 3 (al) shows the case where the substrate is an insulator, and its structure will be explained below according to the manufacturing process.

First, a lower electrode 1 for an element and a lower electrode 2 for a protection diode are separately formed on an insulating substrate 6. Next, a nip element 3 for use as an element or a protection diode is formed, which is an amorphous silicon Lumin element with a P-type doped layer arranged on the light incident surface, or vice versa. and p for the element
After forming the antireflection film 7 on the in element 3a, the upper electrode 4 for the element is formed so that a part thereof is connected to the lower electrode 2 for the protection diode, and the upper electrode 5 for the protection diode is formed. If a part of the solar cell is formed so as to be connected to the lower electrode 1 for the element, an amorphous silicon solar cell with a protection diode is formed.

3) shows a second embodiment of the present invention, in which the substrate is a conductor. In this case, an insulating film 2' is first formed on a part of the substrate 6', and then this A lower electrode 4 for a protection diode is formed in a partial region on the film 2'. In this way, the lower electrode 2 for the protection diode and the substrate eaves serving as the lower electrode for the element are insulated. Next, amorphous silicon pin elements for elements and protection diodes,
Alternatively, a nip element 3 is formed over the above element and the rain lower electrodes 6' and 2 for the protection diode. And then'
Furthermore, the upper electrode 4 for the element and the upper electrode 5 for the protection diode are partially connected to the lower electrode 2 for the protection diode, similar to the embodiment shown in FIG. 3(a). If it is formed so as to be connected to the lower electrode for the element (substrate 6'), an amorphous silicon solar cell with a protection diode is formed.

Note that FIG. 3(0) is an equivalent circuit diagram of FIGS. 3(a) and 3(b).

In the embodiment shown in FIG. 3 (al (b)),
Even if a reverse voltage is applied to an amorphous silicon solar cell (device), the current will flow through the protection diode connected with the opposite polarity, so the amorphous silicon solar cell will not be destroyed. I- in this case
The V characteristic is as shown in FIG. 2, as in the case of a conventional external diode.゛Also, since both the amorphous silicon solar cell and the protection diode have a pin element or a nip element,
It can be manufactured on the same substrate in the same manufacturing process, and the manufacturing process is not increased. In this way, compared to the conventional case where a protection diode is externally attached, the assembly work is greatly simplified and the cost can be reduced.

FIG. 4 shows a third embodiment of the present invention, which is an embodiment in which the lower electrode is not separated between the element and the protection diode. In this case, the element and the protection diode may be formed separately, and the protection diode may be formed in such a way that the polarity of the protection diode is opposite to that of the element.

That is, first, a conductive substrate 6'' is used as a common lower electrode of the element and the protection diode, and a nip element 3a' and an antireflection film 4 are formed as a solar cell on this substrate 6'', and the formation of the solar cell is performed. It is sufficient to form a pin element 3b' as a protection diode in a region different from the area, and then form a common upper electrode 8. Note that when a pin element is used as a solar cell, a nip element is used as the protection diode. .

In such an embodiment, the manufacturing processes for the amorphous silicon solar cell and the protection diode are different, but since there is no need to externally attach the protection diode as in the past, the assembly work is significantly reduced as in the above embodiment. It can be simplified and the cost can be reduced.

Moreover, in the above-mentioned FIG. 3(a) (all the examples shown in bl and FIG. 4)f+ example, a multilayer structure amorphous silicon solar cell can also be used as the amorphous silicon solar cell. That is, Figure 3 (a) (b)
NIP elements (pin elements) are stacked on the amorphous silicon solar cell part shown in FIG. 4 and the amorphous silicon solar cell part shown in FIG. A multilayer structure amorphous silicon solar cell may be used.

For example, in the case of a three-layer solar cell, in the embodiment shown in FIG. 3(a), the lower electrode 1 of the element and the lower electrode 2 of the protection diode are
and pin/p in the solar cell 3a part.
Amorphous silicon may be grown in the order of in/pin (nip/nip/nip), and pin (nip) may be grown in the portion of the protection diode 3b.

In the case of FIG. 3(b), the insulating film 2'' and the lower electrode 2 of the protection diode are formed on the conductive substrate 6' which also serves as the lower electrode of the element, but the amorphous silicon lumen is used. The element 3 part is formed by separating the solar cell and the protection diode. This situation is shown in Fig. 5. First, as a solar cell, pin/pin/pin (nip/ni
Amorphous silicon 3a is grown in the order of p/n1p), and p i n (n i p) is grown in the protective diode part.
All you have to do is grow 3 b.

In the case of Fig. 4, pin/p is attached to the solar cell 3a'' part.
i n/p in (n i p/n i p/n i
It is sufficient to grow amorphous silicon in the order of p) and grow n1p (pin) in the portion of the protection diode 3b'.

In this way, the present invention can also be applied to multilayer solar cells,
As in the above embodiment, assembly work can be simplified and costs can be reduced.

〔Effect of the invention〕

As described above, according to the present invention, since the amorphous silicon solar cell and the protection diode are formed on the same substrate, it is possible to greatly simplify the work when assembling the solar cell module, and to reduce the cost. This has the effect of increasing the

[Brief explanation of drawings]

Fig. 1 is a plan view of a conventional solar cell module, Fig. 2 is an I-V characteristic diagram when a protection diode is attached to a solar cell, and Fig. 3 (a) (bl indicates the first and second parts of this invention. FIG. 3 is a plan view of a photovoltaic device according to an embodiment of the present invention. C1 is shown in Figure 3(a)
An equivalent circuit diagram of the photovoltaic device shown in (b), FIG. 4 is a diagram showing the third embodiment of the present invention, and FIG. It is a block diagram when using. 3a, 3a'...Amorphous silicon pin (n
ip) element (solar cell), 3b, 3b' -... amorphous silicon pin (nip) i-element (protective diode), 6... insulating substrate, 6'... conductive substrate. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Patent Attorney Ken Hayase - Figure 1 Figure 2 ■ 9111151 No. 11''n-11 Figure 4 Figure 5 Procedural Amendment (Voluntary) August 22, 1980 Mr. Commissioner of the Patent Office 1, Incident Display of Tomizu Patent Application No. 59-75331 2, Name of the invention Photovoltaic device 3, Relationship with the case of the person making the amendment Patent applicant address 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name Title
(601) Mitsubishi Electric Co., Ltd. Representative: Katayuni Hachibu 4, Agent address: 4-1-45 Miyahara, Yodoyo-ku, Osaka City, Column 6 of the detailed description of the invention in the specification to be amended, Amendment: Contents (1) “Anti-reflection 11” on page 6, lines 15-16 of the specification
! i4 Correct J to "Anti-reflection film 7". Written amendment to the above procedures (voluntary) December 7, 1980 2. Title of the invention: Photovoltaic device 3. Representative of the person making the amendment: Part 5. Section 5: Detailed explanation of the invention in the specification to be amended. , and drawings (in Figure 3)
) 6. Contents of amendment (1) In the fourth line of page 5 of the specification, "formed." is corrected to "formed, and furthermore, an anti-reflection layer 1117 for the element is formed." (2) Figure 3) is corrected as shown in the attached sheet. that's all

Claims (2)

[Claims] (1) A photovoltaic power generation device characterized by forming on the same substrate an amorphous silicon solar cell and a protection diode made of amorphous silicon that protects the amorphous silicon solar cell from reverse voltage applied thereto. element. (2) Both the amorphous silicon solar cell and the protection diode are made of amorphous silicon pin or n
2. The photovoltaic device according to claim 1, which is manufactured in the same manufacturing process as having an IP device.