Perovskite solar battery and preparation method thereof

1. A perovskite solar battery, comprising a transparent conductive glass substrate, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, and an electrode, wherein the hole transport layer is a nickel oxide hole transport layer; simple- substance nickel and trivalent nickel exists on a contact surface of the hole transport layer in contact with the perovskite light-absorbing layer; and, on the contact surface of the hole transport layer in contact with the perovskite light-absorbing layer, a ratio between simple- substance nickel and trivalent nickel is 85:15 to 99:1.

2. The perovskite solar battery according to claim 1 , wherein no interface passivation material, exists on the contact surface of the hole transport layer in contact with the perovskite light-absorbing layer.

3. The perovskite solar battery according to claim 1 , wherein the perovskite solar battery is an inverted perovskite solar battery.

4. The perovskite solar battery according to claim 1 , wherein a ratio between simple-substance nickel and trivalent nickel is 90:10 to 99:1.

5. The perovskite solar battery according to claim 1 , wherein a ratio between simple-substance nickel and trivalent nickel is 95:5 to 99:1.

6. A method for preparing a perovskite solar battery, comprising the following steps:

S1: providing a transparent conductive glass substrate;

S2: preparing a hole transport layer on the transparent conductive glass substrate;

S3: placing, in an airtight device, the transparent conductive glass substrate on which the hole transport layer is prepared in step S2, and passing a carrier gas and a reductive gas into the airtight device to react;

S4: preparing a perovskite light-absorbing layer on the hole transport layer treated in step s3;

S5: preparing an electron transport layer on the perovskite light-absorbing layer; and

S6: preparing an electrode on the electron transport layer to obtain a perovskite solar battery, wherein

the perovskite solar battery comprises a transparent conductive glass substrate, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, and an electrode;

the hole transport layer is a nickel oxide hole transport layer; simple-substance nickel and trivalent nickel exist on a contact surface of the hole transport layer in contact with the perovskite light-absorbing layer; and, on the contact surface of the hole transport layer in contact with the perovskite light-absorbing layer, a ratio between simple-substance nickel and trivalent nickel is 85:15 to 99:1.

7. The method according to claim 6 , wherein, in step S3, the reductive gas is at least one selected from hydrogen, carbon monoxide, hydrogen sulfide, sulfur dioxide, hydrogen iodide, or ammonia.

8. The method according to claim 6 , wherein, in the step S3, the carrier gas is at least one selected from nitrogen or argon.

9. The method according to claim 6 , wherein, in step S3, a ratio between the carrier gas and the reductive gas is 99:1 to 70:30.

10. The method according to claim 6 , wherein, in step S3, a duration of the reaction is 10 to 60 minutes.

11. The method according to claim 6 , wherein, in step S3, a temperature of the reaction is 150° C. to 250° C.

12. The method according to claim 6 , wherein a ratio between simple-substance nickel and trivalent nickel is 90:10 to 99:1.

13. The method according to claim 6 , wherein a ratio between simple-substance nickel and trivalent nickel is 95:5 to 99:1.