Composite materials for transport layers in perovskite solar cells
Solar cell stack-ups are described in which fullerene based transport layers are blended with a metal halide such as LiF, CsF or MgF 2 . In particular, perovskite solar cell stack-ups are described in which an electron transport layer includes a metal halide and fullerene blend.
1 . A solar cell comprising:
a bottom electrode;
a bottom transport layer over the bottom electrode;
a perovskite absorber layer over the bottom transport layer;
a top transport layer over the perovskite absorber layer, wherein the top transport layer includes a metal halide and fullerene blend, the metal halide is blended throughout an entire thickness of the top transport layer, and the metal halide comprises 20%-60% by volume of the top transport layer; and
a top electrode layer over the top transport layer.
2 . The solar cell of claim 1 , wherein the top transport layer is at least 5 nm thick.
3 . The solar cell of claim 1 , wherein the metal halide is uniformly blended throughout the entire thickness of the top transport layer.
4 . The solar cell of claim 1 , wherein the metal halide comprises 20%-50% by volume of the top transport layer.
5 . The solar cell of claim 1 , wherein the metal halide comprises 20%-40% by volume of the top transport layer.
6 . The solar cell of claim 1 , further comprising a wetting layer between the perovskite absorber layer and the top transport layer.
7 . The solar cell of claim 6 , wherein the wetting layer comprises LiF or fullerene.
8 . The solar cell of claim 1 , further comprising a buffer layer between the top transport layer and the top electrode layer, wherein the top transport layer is an electron transport layer (ETL).
9 . The solar cell of claim 8 , wherein the metal halide comprises Li.
10 . The solar cell of claim 8 , wherein the metal halide comprises F.
11 . The solar cell of claim 8 , wherein the buffer layer comprises a metal oxide.
12 . The solar cell of claim 11 , wherein the metal oxide is doped with aluminum.
13 . The solar cell of claim 11 , further comprising an adhesion layer between the buffer layer and the ETL.
14 . The solar cell of claim 11 , wherein the bottom transport layer, the perovskite absorber layer, and the top transport layer are part of a first subcell of a tandem solar cell, wherein the tandem solar cell further comprises a second subcell underneath the first subcell, the second subcell including a second perovskite absorber layer.
15 . The solar cell of claim 11 , wherein the bottom transport layer, the perovskite absorber layer, and the top transport layer are part of a first subcell of a tandem solar cell, wherein the tandem solar cell further comprises a second subcell underneath the first subcell, the second subcell including a p-doped silicon layer and an n-doped silicon layer.
16 . The solar cell of claim 1 , wherein:
the absorber layer is a perovskite absorber layer.
17 . The solar cell of claim 16 , wherein the metal halide comprises 20%-50% by volume of the top transport layer.
18 . The solar cell of claim 1 , wherein the metal halide comprises F.
19 . The solar cell of claim 16 , further comprising a buffer layer between the top transport layer and the top electrode layer, wherein the metal halide comprises 20%-50% by volume of the top transport layer.
20 . The solar cell of claim 19 , wherein the buffer layer comprises a metal oxide.
21 . The solar cell of claim 1 , wherein the top transport layer is a simultaneously vapor deposited layer of the metal halide and the fullerene.