Enhanced photosensitive properties of a single-crystal formamidinium lead bromide iodine (FAPbBr2I) based photodetector

Abstract

In this work, the growth of formamidinium (FA) based mixed halide perovskite single-crystals using the inverse temperature crystallization method is investigated and characterized to detect their photosensitive properties. The structural characterization of the as-grown single crystals was studied using X-ray diffractometry to confirm whether they belong to the {110} family of planes with a high crystallinity. Their optical properties were studied using UV-Vis spectroscopy, which showed a band-gap of 2 eV, and photoluminescence (PL) spectroscopy. The formation of the Ag/FAPbBr₂I/Ag structure was tested under an applied bias voltage of up to ±5 V using different excitation light sources. The results showed a remarkable photosensitive performance with a peak current of 1 μA with corresponding responsivity and detectivity values of 0.8 A W⁻¹ and 1.81 × 10¹¹ Jones, respectively, under exposure to a visible (376 nm) laser.