Interfacial Engineering Enables Perovskite Heteroepitaxial Growth on Black Phosphorus for Flexible X‐ray Detectors

Abstract

Abstract2D materials with atomic‐scale thickness and mechanical robustness are required for flexible devices. The superior optoelectronic properties and high‐Z atoms in metal halide perovskites render them desirable for X‐ray detection, but the intrinsic brittleness is an obstacle hampering the applications in flexible detectors. Herein, an interfacial engineering strategy is demonstrated for the epitaxial growth of methylammonium lead bromide (MAPbBr3) on black phosphorus (BP) for flexible X‐ray detectors. The mechanically robust, high‐quality heterostructure consisting of a Pb transition layer is synthesized for the two‐way bridging of BP and MAPbBr3. Excellent optoelectronic properties such as a high X‐ray sensitivity of 1,609 ± 122 µC Gy−1 cm−2 (80 times higher than that of the commercial amorphous Se), a fast response time of 40 ± 5 ms, as well as a low detection limit of 3 µGys−1 (about a fifteenth of the medical chest X‐ray dose rate) are achieved from the simple and planar direct X‐ray detector fabricated on an organic filter membrane. More importantly, these flat and simple devices are bendable and mechanically durable by exhibiting only 10% photocurrent degradation after 200 bending cycles. The novel heterostructure has great potential in large‐area, flexible, and sensitive X‐ray detection applications.

Passivation Effect of CsPbBr3 Films Based on SnBr4 Post-Treatment

“…Metal halide-based hybrid perovskites have become a promising material for photovoltaic applications due to their tunable band gap, long carrier diffusion distance, and high absorption coefficient . Consequently, they have garnered extensive attention and application in the fields of solar cells, LEDs, and photodetectors. − Perovskite solar cells (PSCs) have attracted significant attention due to their high power conversion efficiency (PCE) and low manufacturing cost. ,,− Inorganic perovskite CsPbBr 3 has shown remarkable stability against moisture, oxygen, and heat, resulting in increased interest in recent years. It possesses significant potential for use in tandem solar cells and translucent solar cells. − …”