A melt-processable 2D Cd-based ferroelectric semiconductor with a promising X-ray response.

Abstract

2D metal halide perovskites integrating ferroelectricity and solution processability are highly sought-after for advanced optoelectronics, yet concurrent realization of these features, particularly for lead-free systems, poses a persistent challenge. Here, we report a solution-grown 2D cadmium perovskite, (CHA)2CdBr4 (CHA = cyclohexylammonium), which exhibits robust ferroelectricity, a wide liquid-phase stability window (∼170 K), and attractive semiconductor performance. The broad melting window enables the fabrication of large-area, high-quality thin films via melt processing. Consequently, the single-crystal-based X-ray detector achieves a high sensitivity of 1835 µC Gyair s-1 cm-2 and a detection limit of 2.255 nGyair s-1. Our work presents a versatile material platform for low-dose radiation detection and highlights melt-processing as a viable route for flexible device integration.