Lead-Free Cs3Sb2Br9 Single Crystals for High Performance Narrowband Photodetector

Lead-free single crystal perovskite materials exhibit impressive characteristics, such as high carrier mobility, low trap density, and long diffusion length. Herein, the high-performance blue light photodetectors are reported based on lead-free all-inorganic Cs 3 Sb 2 Br 9 perovskite single crystals. These millimeter-sized Cs 3 Sb 2 Br 9 single crystals have small thermal activation energy of 56.8 meV estimated by temperature-dependent photoluminescence study. There is no obvious structural phase transition of the as-obtained Cs 3 Sb 2 Br 9 single crystals since no Raman peak shift is observed with temperature increasing from 80 to 300 K. The as-constructed high quality Cs 3 Sb 2 Br 9 single crystals photodetectors have an excellent performance of a responsivity of 2.29 A W −1 , a sharp detectivity of 3.77 × 10 12 Jones, and an external quantum efficiency (EQE) peak of 1.8 × 10 3 %. Moreover, the photodetectors exhibit a fast response time (<0.2 ms) and the full width at half maximum (FWHM) of the sharp EQE peak is as narrow as 15 nm. This work provides a promising strategy in the design of lead-free, stable, and high-performance perovskites for photodetector devices.