Acoustic-optical phonon up-conversion and hot-phonon bottleneck in lead-halide perovskites.

ABSTRACT: The hot-phonon bottleneck effect in lead-halide perovskites (APbX₃) prolongs the cooling period of hot charge carriers, an effect that could be used in the next-generation photovoltaics devices. Using ultrafast optical characterization and first-principle calculations, four kinds of lead-halide perovskites (A=FA⁺/MA⁺/Cs⁺, X=I^-/Br^-) are compared in this study to reveal the carrier-phonon dynamics within. Here we show a stronger phonon bottleneck effect in hybrid perovskites than in their inorganic counterparts. Compared with the caesium-based system, a 10 times slower carrier-phonon relaxation rate is observed in FAPbI₃. The up-conversion of low-energy phonons is proposed to be responsible for the bottleneck effect

SUBMITTER: Yang J 

PROVIDER: S-EPMC5263885 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature