Pressure-Induced Structural Evolution and Bandgap Optimization of Lead-Free Halide Double Perovskite (NH4)2SeBr6.

ABSTRACT: Lead-free halide double perovskites (HDPs) are promising candidates for high-performance solar cells because of their environmentally-friendly property and chemical stability in air. The power conversion efficiency of HDPs-based solar cells needs to be further improved before their commercialization in the market. It requires a thoughtful understanding of the correlation between their specific structure and property. Here, the structural and optical properties of an important HDP-based (NH4)2SeBr6 are investigated under high pressure. A dramatic piezochromism is found with the increase in pressure. Optical absorption spectra reveal the pressure-induced red-shift in bandgap with two distinct anomalies at 6.57 and 11.18 GPa, and the energy tunability reaches 360 meV within 20.02 GPa. Combine

SUBMITTER: Wang L 

PROVIDER: S-EPMC7080510 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature