Methods for producing and using perovskite materials and devices therefrom
The present disclosure describes solution methods for manufacturing perovskite halide films for use in solar cells. The methods include the use of additives that facilitate the formation of transitory, intermediate films that are later transformed into the final target perovskite halide films, such that the final films provide improved physical characteristics and operational performance.
1. A method comprising:
applying a solution onto a substrate, the solution comprising a first alkyl ammonium halide having a first halogen, a second alkyl ammonium halide having a second halogen, and a metal halide in a solvent; and
treating the solution, wherein:
the first halogen is different than the second halogen,
the treating results in an alkyl ammonium metal halide perovskite film on the substrate, and
the alkyl ammonium metal halide perovskite film includes only one of the first halogen or the second halogen.
2. The method of claim 1 , wherein the metal halide and the second alkyl ammonium halide are present in the solution at a molar ratio of about one to one (1:1).
3. The method of claim 1 , wherein the second alkyl ammonium halide and the first alkyl ammonium halide are present in the solution at a molar ratio between about 1:0.1 and about 1:4.
4. The method of claim 1 , wherein the first alkyl ammonium halide is an alkyl ammonium chloride and the second alkyl ammonium halide is an alkyl ammonium iodide.
5. The method of claim 1 , wherein during the treating, an intermediate alkyl ammonium metal halide perovskite film forms comprising the first halogen and the second halogen.
6. The method of claim 5 , wherein the intermediate alkyl ammonium metal halide perovskite film comprises iodide.
7. The method of claim 6 , wherein the intermediate alkyl ammonium metal halide perovskite film further comprises chloride.
8. The method of claim 5 , wherein the intermediate alkyl ammonium metal halide perovskite film comprises at least one of a methyl ammonium metal iodide and a methyl ammonium metal chloride, or a methyl ammonium metal dihalide comprising iodide and chloride.
9. The method of claim 8 , wherein the alkyl ammonium metal halide perovskite film comprises a methyl ammonium metal iodide.
10. The method of claim 1 , wherein an alkyl group for at least one of the first alkyl ammonium halide or the second alkyl ammonium halide comprises at least one of a methyl group, an ethyl group, a propyl group, or a butyl group.
11. The method of claim 1 , wherein both the first halogen and the second halogen comprise at least one of fluorine, chlorine, bromine, or iodine.
12. The method of claim 11 , wherein the first halogen comprises chloride and the second halogen comprises at least one of bromine or iodine.
13. The method of claim 1 , wherein the metal halide comprises at least one of lead, tin, germanium, or any other metal in a 2+ valence state.
14. The method of claim 1 , wherein the solvent comprises at least one polar solvent.
15. The method of claim 14 , wherein the solvent comprises at least one of dimethysulfoxide, dimethylformamide, γ-butyrolactone, or N-methyl-2-pyrrolidone.
16. The method of claim 1 , wherein at least one of the first alkyl ammonium halide, the second alkyl ammonium halide, or the metal halide are present in the solution at a concentration between about 0.1 M and about 3.0 M.
17. The method of claim 1 , wherein the treating comprises thermally treating.
18. The method of claim 17 , wherein the thermally treating comprises heating the solution at a temperature between about 20° C. and about 250° C.
19. The method of claim 18 , wherein the thermally treating comprises heating the solution for a period of time between about 30 seconds and about 6 hours.