Charge Carriers Are Not Affected by the Relatively Slow-Rotating Methylammonium Cations in Lead Halide Perovskite Thin Films.

ABSTRACT: Recently, several studies have investigated dielectric properties as a possible origin of the exceptional optoelectronic properties of metal halide perovskites (MHPs). In this study we investigated the temperature-dependent dielectric behavior of different MHP films at different frequencies. In the gigahertz regime, dielectric losses in methylammonium-based samples are dominated by the rotational dynamics of the organic cation. Upon increasing the temperature from 160 to 300 K, the rotational relaxation time, τ, decreases from 400 (200) to 6 (1) ps for MAPb-I₃ (-Br₃). By contrast, we found negligible temperature-dependent variations in τ for a mixed cation/mixed halide FA_0.85MA_0.15Pb(I_0.85Br_0.15)₃. From temperatur

SUBMITTER: Caselli VM 

PROVIDER: S-EPMC6734799 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature