Extended carrier lifetimes and diffusion in hybrid perovskites revealed by Hall effect and photoconductivity measurements.

ABSTRACT: Impressive performance of hybrid perovskite solar cells reported in recent years still awaits a comprehensive understanding of its microscopic origins. In this work, the intrinsic Hall mobility and photocarrier recombination coefficient are directly measured in these materials in steady-state transport studies. The results show that electron-hole recombination and carrier trapping rates in hybrid perovskites are very low. The bimolecular recombination coefficient (10(-11) to 10(-10)?cm(3)?s(-1)) is found to be on par with that in the best direct-band inorganic semiconductors, even though the intrinsic Hall mobility in hybrid perovskites is considerably lower (up to 60?cm(2)?V(-1)?s(-1)). Measured here, steady-state carrier lifetimes (of up to 3?ms) and diffusion lengths (as long as 650??m) are significantly longer than those in high-purity crystalline inorganic semiconductors. We suggest that these experimental findings are consistent with the polaronic nature of charge carriers, resulting from an interaction of charges with methylammonium dipoles.

SUBMITTER: Chen Y 

PROVIDER: S-EPMC4974647 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature