A Dense, Pinholes-free Pure Cubic Phase CsPbBr3 Nanocrystals Film for High-performance Photodetector

Abstract

This study demonstrates a simple centrifugal coating method to prepare high-quality pure cubic phase CsPbBr₃ nanocrystal film. The resultant perovskite layers possess a uniform and dense 500 nm-thick, with a bandgap of 2.38 eV, a low trap-state density of 6.9 × 10^− 15 cm^− 3, and carrier mobility of approximately 19.8 cm²V^− 1s^− 1. Furthermore, CsPbBr₃ NCs-based self-powered photodetectors with high charge carriers’ charge transfer are fabricated. The device shows a low dark current density of 1.93 × 10^− 7 A/cm² at room temperature. Such photodetectors show the highest responsivity of 3.0 AW^− 1, specific detectivity of 1.2 × 10¹³ Jones, and external quantum efficiency (EQE) of 920% at zero bias voltage. The proposed method shows significant promise for use in the lab fabrication of optoelectronic devices based on thin films of nanocrystal perovskite materials.