Speaker
Description
All-inorganic CsPbBr₃ perovskite has emerged as a potential material for optoelectronic applications such as solar cells, LEDs, photodetectors, and X-ray detectors, owing to its superior charge-transport properties, long carrier diffusion length, and broad light absorption.¹ In contrast to its organic counterparts such as MAPbBr₃ (MA = methylammonium), all-inorganic CsPbBr₃ exhibits superior photostability, thermal stability, and moisture stability, making it a suitable candidate for high-energy radiation detection.²
Dimethyl sulfoxide (DMSO) is a widely used solvent for the synthesis of halide perovskites (HPs); nevertheless, its intrinsically high viscosity and boiling point can lead to degradation and reduced optoelectronic performance in the resulting perovskite films due to DMSO trapping during film formation, which generates voids.³ One of the major issues with CsPbBr₃ is the large dark current generated by the intrinsic ionic-migration nature of the material.² Such large dark currents can compromise device stability and degrade X-ray image quality.
In this presentation, I will discuss the synthesis of CsPbBr₃ microcrystals (~20/50 μm) for X-ray detection. I will elaborate on the impact of washing these DMSO-synthesized microcrystals with different solvents (such as ethanol (EtOH) and ethyl acetate (EA)) and examine how these solvents affect the structural, optical, and X-ray detection properties of CsPbBr₃ microcrystals. To evaluate their practical applicability, proof-of-concept X-ray detectors based on wafers composed of these microcrystals have been developed.
Compared with their non-washed counterparts, CsPbBr₃ microcrystals washed with a combination of EA and EtOH exhibit reduced dark current and suppressed dark-current drift. This reduction in dark current leads to an improved on/off ratio and an X-ray limit of detection (LoD) enhanced by more than one order of magnitude.
(1) Clinckemalie, L. et al. Phase-Engineering Compact and Flexible CsPbBr3 Microcrystal Films for Robust X-Ray Detection. J. Mater. Chem. C 2024, 12 (2), 655–663.
(2) Clinckemalie, L. et al. Challenges and Opportunities for CsPbBr3 Perovskites in Low- and High-Energy Radiation Detection. ACS Energy Lett. 2021, 6 (4), 1290–1314.
(3) Chen, S. et al. Stabilizing Perovskite-Substrate Interfaces for High-Performance Perovskite Modules. Science 2021, 373 (6557), 902–907.