Solution‐Processed Amorphous Zero‐Dimensional Organic Metal Halide Hybrid Films for Direct X‐Ray Detectors

Abstract Zero‐dimensional (0D) organic metal halide hybrids (OMHHs) are emerging materials with significant potential for optoelectronic applications, including direct X‐ray detectors. While 0D OMHH single crystals exhibit excellent X‐ray detection properties, their scalability remains a significant challenge due to the time‐intensive growth process and difficulty in producing large single crystals exceeding a few centimeters. This limitation hinders their practicality for large‐area detector applications. Here, we report for the first time the development of amorphous 0D OMHH films via solution processing for efficient direct X‐ray detection. By reacting a non‐crystalline organic halide, triphenyl(9‐phenyl‐9H‐carbazol‐3‐yl)phosphonium bromide (TPPCarzBr), with zinc bromide (ZnBr 2 ), we have successfully produced amorphous 0D (TPPCarz) 2 ZnBr 4 films with controlled thickness via facile solution processing. The organic cations (TPPCarz⁺) feature a lower bandgap than the ZnBr 4 2− anions, enabling efficient molecular sensitization, where ZnBr 4 2− anions serve as X‐ray absorbers and TPPCarz⁺ cations as charge transporters. Direct X‐ray detectors based on 0D (TPPCarz) 2 ZnBr 4 films demonstrate outstanding performance, achieving a stable X‐ray detection sensitivity of 2,165 µC Gy air ⁻ 1 cm⁻ 2 at 20 V mm⁻¹ and a detection limit of 6.01 nGy air s⁻¹. The amorphous nature of these films enhances their processability, allowing for fabrication in various sizes and shapes, and making them highly adaptable for scalable detector applications.