Solar cells with perovskite-based light sensitization layers
Solar cells are provided which comprise an electron transporting layer and a light sensitizing layer of perovskite disposed over the surface of the electron transporting layer. The perovskite may have a formula selected from the group consisting of A 2 MX 6 , Z 2 MX 6 or YMX 6 , wherein A is an alkali metal, M is a metal or a metalloid, X is a halide, Z is selected from the group consisting of a primary ammonium, an iminium, a secondary ammonium, a tertiary ammonium, and a quaternary ammonium, and Y has formula M b (L) 3 , wherein M b is a transition metal in the 2+ oxidation state L is an N—N neutral chelating ligand. Methods of making the solar cells are also provided, including methods based on electrospray deposition.
1. A method of making a perovskite sensitizing layer, the method comprising electrospraying a solution comprising a perovskite on the surface of an electron transporting layer, and heating the perovskite sensitizing layer at a temperature for a time, wherein the perovskite sensitizing layer is formed on the surface of the electron transporting layer, wherein the perovskite has a formula selected from the group consisting of A 2 MX 6 , Z 2 MX 6 and YMX 6 ,
wherein A is an alkali metal,
M is a metal or a metalloid,
X is a halide,
Z is selected from the group consisting of a primary ammonium, an iminium, a secondary ammonium, a tertiary ammonium, and a quaternary ammonium, and
Y has formula M b (L) 3 , wherein M b is a transition metal in the 2+ oxidation state L is an N—N neutral chelating ligand.
2. A method of making a perovskite sensitizing layer, the method comprising:
(a) exposing an electron transporting layer to a first solution comprising a first perovskite precursor to form a first coating on the surface of the electron transporting layer and heating the coated electron transporting layer at a first temperature for a first time; and
(b) exposing the coated electron transporting layer to a second solution comprising a second perovskite precursor to form a second coating over the surface of the electron transporting layer and heating the coated electron transporting layer at a second temperature for a second time, wherein the perovskite sensitizing layer is formed on the surface of the electron transporting layer, wherein the perovskite has a formula selected from the group consisting of A 2 MX 6 , Z 2 MX 6 and YMX 6 ,
wherein A is an alkali metal,
M is a metal or a metalloid,
X is a halide,
Z is selected from the group consisting of a primary ammonium, an iminium, a secondary ammonium, a tertiary ammonium, and a quaternary ammonium, and
Y has formula M b (L) 3 , wherein M b is a transition metal in the 2+ oxidation state L is an N—N neutral chelating ligand.
3. The method of claim 2 , wherein the first perovskite precursor is selected from the group consisting of AX, ZX and YX 2 ; and further wherein the second perovskite precursor is MX 4 .
4. The method of claim 1 , wherein the perovskite has the formula A 2 MX 6 .
5. The method of claim 4 , wherein the electron transporting layer is a mesoporous electron transporting layer comprising nanostructures that define pores.
6. The method of claim 5 , wherein the perovskite sensitizing layer is sufficiently thin that it does not fill the pores of the electron transporting layer.
7. The method of claim 4 , wherein the perovskite comprises Cs 2 SnI 6 .
8. The method of claim 1 , wherein the perovskite has the formula Z 2 MX 6 .
9. The method of claim 1 , wherein the perovskite has the formula YMX 6 .
10. The method of claim 3 , wherein the perovskite has the formula A 2 MX 6 .
11. The method of claim 10 , wherein the electron transporting layer is a mesoporous electron transporting layer comprising nanostructures that define pores.
12. The method of claim 11 , wherein the perovskite sensitizing layer is sufficiently thin that it does not fill the pores of the electron transporting layer.
13. The method of claim 11 , wherein the first perovskite precursor has the formula AX and the second perovskite precursor has the formula MX 4 , wherein A is an alkali metal, M is a metal or a metalloid, and X is a halide.
14. The method of claim 13 , wherein AX is CsI, MX 4 is SnI 4 , and the perovskite is Cs 2 SnI 6 .
15. The method of claim 2 , wherein the electron transporting layer is a mesoporous electron transporting layer comprising nanostructures that define pores.
16. The method of claim 15 , wherein the perovskite sensitizing layer is sufficiently thin that it does not fill the pores of the electron transporting layer.
17. The method of claim 3 , wherein the perovskite has the formula Z 2 MX 6 .
18. The method of claim 17 , wherein the first perovskite precursor has the formula ZX and the second perovskite precursor has the formula MX 4 , wherein M is a metal or a metalloid, X is a halide, and Z is selected from the group consisting of a primary ammonium, an iminium, a secondary ammonium, a tertiary ammonium, and a quaternary ammonium.
19. The method of claim 3 , wherein the perovskite has the formula YMX 6 .
20. The method of claim 19 , wherein the first perovskite precursor has the formula YX 2 and the second perovskite precursor has the formula MX 4 , wherein M is a metal or a metalloid, X is a halide, and Y has formula M b (L) 3 , wherein M b is a transition metal in the 2+ oxidation state L is an N—N neutral chelating ligand.