JPS6322632B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solar cell with a power storage function. Conventional solar cells generate electricity by irradiating sunlight, and do not generate electricity when sunlight is not irradiating them. For this reason, it was common practice to generate electricity using sunlight during the day and store the surplus electricity for use at night. Therefore, when using electricity continuously, only a combination of solar cells and storage batteries can be used, and there is no system that has the function of notifying the outside of the presence or absence of electricity storage.

The present invention has been proposed in view of the above points, and an object of the present invention is to provide a solar cell with a power storage function that has the function of a storage battery that stores the amount of electricity generated as it is, and also allows the amount of stored power to be easily determined from its appearance. This is the purpose.

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

FIG. 1 shows an embodiment of the present invention, in which 1 is glass, 2 is a transparent electrode formed on the lower surface of the glass,
3a is an N-type semiconductor layer formed on the lower surface of the transparent electrode 2; 3b is a P-type semiconductor layer formed on the lower surface;
4 is an intermediate electrode on the lower surface thereof, and the solar cell 3 is formed by the N-type semiconductor layer 3a and the P-type semiconductor layer 3b. Further, 5 is an intermediate layer formed on the lower surface of the intermediate electrode 4, 6 is an electrochromic film (layer) on the lower surface, and 7 is an electrode, and this electrode 7 and the transparent electrode 2 are electrically connected. ,
Further, the intermediate electrode 4 and the electrode 7 are also connected via a resistor R.

In the above, the transparent electrode 2 is In ₂ O ₃ ,
Thin films such as SnO ₂ and In ₂ O ₃ +SnO ₂ are used. Further, as the solar cell 3, a silicon single crystal, amorphous silicon, MIS type, group, selenium photovoltaic cell, or the like is used. As the intermediate electrode 4, a thin film of Au, Ag, Pt, C+ metal oxide, etc. is used. As the intermediate layer 5, a solid electrolyte (PbAg ₄ I ₅ , Na ₃ Zr _2- SiPO ₁₂ , Na ₅ YSiO ₁₂ etc.) is used.
In addition, dielectric materials (CaF ₂ , MgF ₂ , LiF, SiO, ZrO ₂ ,
Cr ₂ O ₃ etc.) are used.

As the electrochromic film layer 6, WO ₃ ,
_MoO3 , _TiO2 , _SrTiO3 , _{Fe2O3 ,} ZnO, _TeO2 ,
_Sb2O3 , _SeO2 , _BaO , _Bi2O3 , _CaF2 , _{SnO2 ,
InO3 , V2O5} , _{Cr2O3 ,} CdS, _As2O3 , _{GeO2 ,}
MnO ₂ etc. are used. The electrode 7 is made of the same material as the transparent electrode 2 described above.

Thus, the WO ₃ (tungsten trioxide) type electrochromic display used as the electrochromic film layer 6 changes color from white to tungsten blue when voltage is applied.

As shown in Figure 2a, when this WO ₃ type display changes from white to tungsten blue (blue) by applying a voltage, it changes by about 1
The blue color remains as it is for about a month. To return the color from blue to white, a reverse voltage may be applied as shown in b.

In this case, the inventor noticed that the fact that the color changes from white to blue and continues as it is (without applying voltage) indicates that electricity is being stored, and that the display element that has turned blue can be fully used as a battery. It is understood that in view of these points, a solar cell with a power storage function configured as described above was invented.

Furthermore, since the display element and the solar cell are both constructed using thin films, the present invention has the great advantage that two functions can be simultaneously created on one substrate.

The film layers are applied using glass 1 as a substrate and all layers are sequentially heated using resistance heating or an electron beam evaporator in a vacuum of 10 ^-4 to 10 ^-6 Torr at a substrate temperature of 25 to 100°C.
It was deposited under The thickness of the deposited film varies depending on the layer, but is approximately 2000 Å to several microns.

Next, the operation of the present invention will be explained.

First, when the transparent electrode 2 is irradiated with sunlight through the glass 1, a voltage is generated between the transparent electrode 2 and the electrode 4. Since this is the same principle of operation of general solar cells, it will be omitted here.

In this case, the transparent electrode 2 has (-),
The electrode 4 is set so that a (+) voltage is generated.

Next, since the WO ₃ electrochromic display element section and the solar cell 3 are connected in parallel, the display element changes from white to blue. This principle is
By protons injected into _WO3 It is thought that the formula is In addition, Mx means H ⁺ ,
These are protons such as Li ⁺ , Na ⁺ , and Ag ⁺ .

Therefore by proton injection MxWO ₃ (blue)
is stored electricity, and if protons are removed from the outside, it returns to its original state and becomes WO ₃ , which becomes white.

As explained above, it will be explained again here that when a voltage is applied to the front element, the color changes from white to blue (see FIG. 2a). To return it to its original state, you can apply a reverse voltage (see b), but even if you shoot the electrode, the color returns from blue to white. At this time, current flows.

That is, as shown in FIG. 2c, when a load resistor is connected to a blue display element, the color gradually changes from blue to white. At that time, the amount of electricity charged will be discharged. This can be applied as a storage battery.

In order to configure it on the same substrate as the solar cell 3, various conditions must be met. In other words, the amount of power generation, amount of charge, voltage, etc. need to match.

To explain this, first of all, regarding the amount of power generated, silicon single crystal, amorphous silicon solar cells, etc. generate 0.5V to 0.8V and can take a current of 1mA to 10mA/cm ² .

On the other hand, for the display element (in the case of 1 cm ² ), the operating voltage changes from white to blue at 0.5 V to 0.8 V, and this range is optimal. In this case, the operating current is several hundred μA ~
It is several mA. However, the amount of electricity stored at this time is
20mC (milikiury) to several C (in the case of ^1cm2 ). This amount of charge is when considered as a display element. If the purpose is simply to increase the amount of electricity stored, it can be controlled by increasing the amount of _WO3 .

Example: If 1C (coulomb)/cm ² of electricity is stored and applied to a household wall clock, then C=
It is 0.277mAH (milliamp hour). Assuming that the amount of electricity consumed by the watch is 10μA, 0.277mAH/10μA=0.277× ^10-3 AH/10× ^10-6 A=0.027
7×10 ³ H = 27.7 hours Therefore, once this device is charged, it will operate for 27.7 hours without irradiation with light.

Examples of the present invention will be set forth below.

Example (1) First, a conductive thin film (transparent electrode 2) is applied to glass 1. The material is an In ₂ O ₃ film formed to a thickness of 5000 Å using an electron beam evaporator.

(2) Form an amorphous silicon solar cell 3 on the film. This amorphous solar cell 3 is made by heating the substrate to 300℃ and adding silane (SiH ₄ ) to it.
A doping gas of fasufine is mixed with a raw material gas of hydrogen (H ₂ ) and an N-type layer is formed by glow discharge between the electrodes, and a doping gas of diborane is mixed thereon to form a P-type layer in the same manner.
At this time, a thickness of approximately 1 μm was sufficient.

(3) Electrode 4 is a (+) electrode and a thin Aμ film is applied to a thickness of 5000 Å.

(4) The intermediate layer 5 is made of solid electrolyte RbAg ₄ I ₅ with a thickness of about 1000 Å. Attach using electron beam evaporation method.

(5) WO ₃ as electrochromic film layer 6
is applied to a thickness of 1 to 2 μm by electron beam evaporation.

(6) Electrode 7 is an In ₂ O ₃ transparent electrode attached by electron beam evaporation.

When the product of the present invention constructed as above and wired with electrodes as shown in Figure 1 is irradiated with solar light at right angles, a voltage of 0.8V is generated between the electrode terminals, and after 10 seconds, the electrode 7 side turns white. changed from to blue. Next, when we turned off the sunlight and ran the clock, which consumes 10 μA, in a dark room, it ran for about 27 hours. (Since the clock operated at 1.5V, I connected two of the products of this invention in series). In addition,
If you leave it in a dark room with no load after the light goes off, it will still generate about half the amount of electricity even after a month.

According to the present invention configured as described above, since a solar cell and a storage battery can be formed on a single substrate,
It has a large economic effect.

In addition, since the back surface (electrode side) changes from white to blue as electricity is stored, it has the advantage of being able to tell at a glance the state of charge or storage.

[Brief explanation of the drawing]

FIG. 1 is a solar cell with a power storage function according to the present invention, and FIGS. 2 a to 2 c are explanatory views of the operation of the present invention. DESCRIPTION OF SYMBOLS 1... Glass, 2... Transparent electrode, 3... Solar cell, 4... Intermediate electrode, 5... Intermediate layer, 6... Electrochromic film (layer), 7... Electrode.

Claims (1)

[Claims] 1. A solar cell in which a transparent electrode with glass on its surface is provided on one surface and an intermediate electrode on the other surface, and a WO ₃ type solar cell in which an intermediate electrode is provided on the outer surface of the intermediate electrode via an intermediate layer. A solar device with a power storage function, comprising an electrochromic layer and an electrode provided on the outer surface of the electrochromic layer, and the electrode is electrically connected to the transparent electrode and the intermediate electrode, respectively. battery.