JPH01259573A - Secondary photo cell - Google Patents

Abstract

PURPOSE:To improve light charging efficiency by integrating a photovoltaic force generation part consisting of amorphous silicon and metallic copper, and a secondary cell part consisting of a copper ion conductive solid electrolyte and Cu MS2 with metallic copper as a common part. CONSTITUTION:An amorphous silicon layer 3 and an I-type amorphous silicon layer 4 are formed on a transparent electrode 2 and a metallic copper layer 5 is formed on this layer by a vacuum heat deposition method. Next, a TiS2 layer 7 is formed on a collector electrode 8 and finally a solid electrolyte layer 6 to be expressed by RbCu4I1.75Cl3.25 is formed; the whole is coated with epoxy resin 9. Then, a photovoltaic generation part consisting of amorphous silicon and metallic copper is irradiated by light, a secondary cell part formed of metallic copper, a copper ion conductive solid electrolyte and CuxMS2 comes to be charged by the photoelectromotive force. Thereby, the light charging efficiency due to recombination of holes and electrons inside CuxMS2 can be improved.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention has both the functions of a solar cell that generates a photovoltaic voltage and a normal secondary battery, and in particular functions as an uninterruptible power source for driving various power consumption devices. It is used in photo secondary batteries with.

2. Description of the Related Art Many power supply devices have been proposed that can be used as a power source regardless of day or night by storing solar energy as electric power. (Electronics by Masao Kaneko
P97-104, 1982) However, what is currently in practical use is a two-device integrated type that stores the electricity generated by solar cells in a secondary battery and uses it at night. Since the power generation part and the charging part are each independent, the device configuration is complicated and large.

In response, the inventors proposed a photo secondary battery that has both the functions of a solar cell that generates a photovoltaic voltage with a single element and a normal secondary battery (Japanese Patent Application Laid-Open No. 118974/1982).

Problems to be Solved by the Invention However, the photo-charging efficiency, that is, the ratio of charging current to manually irradiated light, in the photo secondary battery is low.

Means for Solving the Problems A photovoltaic voltage generating part was created using amorphous silicon and metal copper, and a secondary battery part made of a copper ion conductive solid electrolyte and C, u x M S 2 was created using the metal copper as a common part. Create and integrate.

The reason for the low photocharging efficiency of the photovoltaic secondary battery described in the conventional example described above is considered to be as follows. In other words, this photosecondary battery is mainly made of a compound represented by Cu x M S 2, which has a structure in which copper atoms are coordinated between layers of a layered compound having MB2 as a skeleton.

The photocharging reaction was such that when MB2 was irradiated with light, a hole was created in the valence band of MB2, which reacted with the copper atoms coordinated between the eyebrows. However, in the above reaction, the bond between MB2 and the copper atom is very weak, and the holes generated in the valence band of MB2 are rather more likely to recombine with the electrons excited in the conduction band, which reduces the photocharging reaction efficiency. It is thought that it was low. In the present invention, a photovoltaic voltage generating part is formed by amorphous silicon and metallic copper, and when this part is irradiated with light, metallic copper, copper ion conductive solid electrolyte, C
The secondary battery part formed by u xM S 2 is charged with the electric power generated by the photovoltaic voltage generation part, and the efficiency is increased by the recombination of the poles and electrons inside CIJ XM S 2 as described above. No decline will occur.

Example (Example 1) FIG. 1 shows the structure of a photo secondary battery which is an example of the present invention. ITO made of a compound of In2O3 and SnO2 is grown on a glass substrate 1 with a size of 20 x 20 mm and a thickness of 1 mm, with a transparent electrode 2 on one side and a current collecting electrode 8 on the other side.
And so. Next, an amorphous silicon layer 3 was formed on 1 of the transparent electrode 2 to a thickness of 0.04 μm by the CVD method, and then B was doped as an impurity to give it P-type semiconductor characteristics.

Further, an I-type amorphous silicon layer 4 having a thickness of 0.4 μm is continuously formed by the above CVD method. A metal copper layer 5 having a thickness of 10 .mu.m was formed on the above-described amorphous silicon layer by vacuum heating evaporation. Next, 10 μm of Ti52F'7 was formed on the current collector electrode 8 formed at the same time as the transparent electrode 2 by the plasma CVD method, and finally, Rb C11a I I , 75C13 was formed by the vacuum heating evaporation method.
, 25 was formed to a thickness of 10 μm, and the entire body was coated with epoxy resin 9 to obtain battery A of this example. Note that 10 is a negative electrode lead terminal made of ITO that was created at the same time as the transparent electrode was created, and is connected to the metal copper layer 5.
It is electrically connected to the

The operating mechanism of battery A produced in this manner will be described below. Metallic copper has a smaller number of work hours than amorphous silicon, so when light is irradiated on the junction surface between the P-1 amorphous silicon and metal copper, a photoelectromotive voltage is generated, and the metal copper has a negative voltage and the P-type amorphous silicon has a positive voltage. voltage. Therefore, when the transparent electrode 2 electrically connected to the P-type amorphous silicon and the current collecting electrode 8 electrically connected to the TiS2 are electrically connected, a positive voltage is applied to the TiS2, and the metal copper and the solid electrolyte The secondary battery formed by this will be charged.

When the external electric device is connected between the transparent electrode 2 and the current collecting electrode 8, the external electric device is driven simultaneously with the above charging reaction. In addition, when light irradiation is not performed such as at night, the electric power charged in the secondary battery part during light irradiation is used through the current collector electrode 8 and the negative lead terminal 10 to create an uninterruptible power source that can be used day or night. It can be used as

As a comparative example, a photo-chargeable battery B was created through an oxidation reaction between holes generated by irradiating a semiconductor electrode with light and the first battery active material electrode. A sectional view thereof is shown in FIG. A glass substrate 11 having a size of 20×20 mm and a thickness of 1 mm was made of 2 mm of ITO on which a transparent electrode 12 was smoke-steamed on one side and a current collecting electrode 13 on the other. Next, Zr is placed on the transparent electrode 12.
After forming the S2 layer 14 to a thickness of 10 μm by RF sputtering, metal copper r=t is subsequently deposited on the current collecting electrode 13 formed at the same time as the transparent electrode 12 by vacuum heating evaporation.
5 was formed with IOl, 1 m. Finally, a 10 μm thick solid electrolyte layer 16 represented by Rb Cu a I 1.75 CI 3.25 was formed by the vacuum heating vapor deposition method, and the entire body was coated with an epoxy resin 17 to obtain a battery B of a comparative example.

The following tests were conducted on batteries A and B produced by the above method. First, as an external load, 100Ω
Using a fixed resistor, we measured the voltage across the fixed resistor while intermittently irradiating it with light. The results are shown in FIG. The vertical axis shows the terminal voltage of the battery, and the horizontal axis shows the elapsed time. In addition, the connection of the fixed resistor is such that in battery A, terminal 2 is the positive pole and terminal 8 is the negative pole when irradiated with light, and in the dark state, 8 is switched as the positive pole and IO is the negative pole, and in battery B, when the light is irradiated, terminal 13 is the positive pole and terminal 12 is the negative pole. 5. In the dark state, terminals 13 were connected as negative terminals and terminals 12 were positive terminals. A too-lux white fluorescent lamp was used as the light source, and irradiation and non-irradiation were repeated in a 2-hour period.

As is clear from FIG. 3, the terminal voltage of battery B of the comparative example decreases with time. This is thought to be because the charging efficiency during light irradiation is low, so the charging of the secondary battery part is insufficient for the power required to drive the external load. On the other hand, in battery A of this example, no decrease in terminal voltage was observed even with intermittent light irradiation cycles, and this solved the problem of the conventional case of low charging efficiency during light irradiation. It can be said that it was done.

(Example 2) Battery C of Example 1 was manufactured using the same battery configuration and manufacturing method except that NbS2 was used instead of TiS2 in Battery A of Example 1. On the other hand, the same performance evaluation test as in Example 1 was conducted. The results are shown in FIG. As can be seen from this figure, the battery C of this example also satisfactorily functions as an uninterruptible power supply.

[Brief explanation of the drawing]

Fig. 1 is a structural diagram of battery A as an example of the present invention, Fig. 2 is a structural diagram of battery B as a comparative example, Fig. 3 is a characteristic diagram of battery A, and Fig. 4 is a different embodiment of the present invention. FIG. 2 is a characteristic diagram of battery C. 1... Glass substrate, 2... Transparent electrode, 3... P-type amorphous silicon layer, 4... ■-type amorphous silicon layer, 5... Metallic copper layer, 6... Solid electrolyte layer,
7...TiS2 layer, 8...Collecting electrode, 9...Epoxy resin, 10...Negative electrode...de terminal, 11.
...Glass substrate, 12...Transparent electrode, 13...Collecting electrode, 14...Zr52N, 15...Metal copper layer, 1
6... Solid electrolyte layer, 17... Epoxy resin. Name of agent Patent attorney Toshio Nakao 1 person Figure 1 Figure 2 Figure 1'3 Current collector Figure 3 0 4-8 12 76 K Passage distance (hours) Figure 4 Ship passage 4 hours (hours) )

Claims (1)

[Claims] P-type amorphous silicon, I-type amorphous silicon, metallic copper, copper ion conductive solid electrolyte, Cu×MS_
2 (0<=X<=0.15, M is either Ti or Nb), and the P A photovoltaic voltage is generated between the amorphous silicon type and the metal copper, whereby a photovoltaic voltage is generated between the metal copper, the copper ion conductive solid electrolyte, and Cu_xMS_2.