Clearly Discriminate the Continuum Band and Exciton State of the Hybrid Lead Bromide Perovskite

Abstract

Electronic states of the hybrid perovskite enable their promising applications as distinctive optoelectronic materials. The understanding of their electronic structures and charge characters remains highly controversial. The electronic mechanism such as reabsorption, Urbach tail and indirect band for interpreting dual-peak emissions is one of the controversial focuses. Herein, we report that through heterojunction enhanced exciton dissociation and global tracing of multiple radiative electronic states across wide temperature regions, we have succeeded in directly observing free carrier emissions from the hybrid lead bromide perovskite and clearly discriminating the direct continuum band and exciton states. The widely-concerned dual-peak emissions are clarified to be excitonic, arising from two types of exciton states of the perovskite. These excitons possess giant binding energies and superior phase stability compared to conventional inorganic semiconductors, providing important implications for exploiting the excitonic mechanism for realizing novel optoelectronic applications.

References in corpus (4)

• Indirect to direct bandgap transition in methylammonium lead halide perovskite
• Giant Rashba Splitting in CH3NH3PbBr3 Organic-Inorganic Perovskite
• Identification of Free and Bound Exciton States and Their Phase-Dependent Trapping Behavior in Lead Halide Perovskites
• Low-threshold Stimulated Emission of Hybrid Perovskites at Room Temperature through Defect-Mediated Bound Excitons

Cited by in corpus (2)

• Room-temperature exceptional-point-driven polariton lasing from perovskite metasurface
• Polaron-enhanced polariton nonlinearity in lead halide perovskites