Method for preparing perovskite film and solar cell thereof

1. A method for preparing a perovskite film, comprising steps of:

applying a first solution on a substrate to form a film by spin coating; and

applying a second solution on the film made from the first solution to form the perovskite film, which is expressed by a general formula of ABX 3 by spin coating,

wherein the solute of the first solution at least contains one of AX and BX 2 , and the solute of the second solution at least contains one of AX and BX 2 .

2. The method for preparing a perovskite film as recited in claim 1 , wherein A represents at least one of alkali metal ions, methylamine ions, ethylamine ions, NH 2 CH═NH 2 ions or alkylamine ions, B represents at least one of the group IV element (Ge, Sn, Pb), the group III indium (In) and the group V antimony (Sb), and X represents at least one of the elements of the group VII (F, Cl, Br, I).

3. The method for preparing a perovskite film as recited in claim 1 , wherein each of the solvents of the first and second solutions is DMF or isopropanol or the mixture of the two.

4. A method for preparing a solar cell using a perovskite film as an active layer, comprising steps of:

providing a conductive material;

forming a first carrier transport layer on the conductive material;

applying a first solution on the first carrier transport layer to form a film by spin coating;

applying a second solution on the film made from the first solution to form the perovskite film, which is expressed by a general formula of ABX 3 by spin coating;

forming a second carrier transport layer on the perovskite film; and

forming an electrode layer on the second carrier transport layer,

wherein the solute of the first solution at least contains one of AX and BX 2 , and the solute of the second solution at least contains one of AX and BX 2 .

5. The method for preparing a solar cell as recited in claim 4 , wherein A represents at least one of alkali metal ions, methylamine ions, ethylamine ions, NH 2 CH═NH 2 ions or alkylamine ions, B represents at least one of the group IV element (Ge, Sn, Pb), the group III indium (In) and the group V antimony (Sb), and X represents at least one of the elements of the group VII (F, Cl, Br, I).

6. The method for preparing a solar cell as recited in claim 4 , wherein each of the solvents of the first and second solutions is DMF or isopropanol or the mixture of the two.

7. The method for preparing a solar cell as recited in claim 4 , wherein the conductive material is a transparent conductive glass or an opaque conductive material.

8. The method for preparing a solar cell as recited in claim 4 , wherein the first carrier transport layer is a hole transport layer or an electron transport layer, the second carrier transport layer is an electron transport layer or a hole transport layer, and the electrode layer is a cathode layer or an anode layer.

9. The method for preparing a solar cell as recited in claim 8 , wherein the material of the hole transport layer is PEDOT:PSS (Poly(3,4-ethylenedioxythiophene) Polystyrene sulfonate), 2,2′,7,7′-Tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirobifluorene (Spiro-OMeTAD), V 2 O 5 , NiO, WO 3 or MoO 3 .

10. The method for preparing a solar cell as recited in claim 8 , wherein the material of the electron transport layer is LiF, Ca, 6,6-phenyl-C61-butyric acid methyl ester (PC 61 BM), 6,6-phenyl-C71-butyric acid methyl ester (PC 71 BM), Indene-C60 bisadduct (ICBA), Cs 2 CO 3 , TiO 2 , poly[(9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene) (PFN), Bathocuproine (BCP), ZnO, ZrO.

11. The method for preparing a solar cell as recited in claim 8 , wherein the material of the electrode layer is Ca, Al, Ag, Au or their any combination.