Why lead methylammonium tri-iodide perovskite-based solar cells require a mesoporous electron transporting scaffold (but not necessarily a hole conductor).
CH3NH3PbI3-based solar cells were characterized with electron beam-induced current (EBIC) and compared to CH3NH3PbI(3-x)Clx ones. A spatial map of charge separation efficiency in working cells shows p-i-n structures for both thin film cells. Effective diffusion lengths, LD, (from EBIC profile) show that holes are extracted significantly more efficiently than electrons in CH3NH3PbI3, explaining why CH3NH3PbI3-based cells require mesoporous electron conductors, while CH3NH3PbI(3-Clx ones, where LD values are comparable for both charge types, do not.
Department of Materials and Interfaces, Faculty of Chemistry, Weizmann Institute of Science , 76100, Rehovot, Israel.
Eran
E
Edri
Saar
S
Kirmayer
Alex
A
Henning
Sabyasachi
S
Mukhopadhyay
Konstantin
K
Gartsman
Yossi
Y
Rosenwaks
Gary
G
Hodes
David
D
Cahen