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

Area of Science:

• Materials Science
• Optoelectronics
• Detector Technology

Background:

• Zero-dimensional organic metal halide hybrids (0D OMHHs) show promise for optoelectronic devices, particularly direct X-ray detection.
• Current 0D OMHH single crystals have excellent X-ray detection properties but face scalability challenges due to difficult and time-consuming crystal growth.
• The limited size of single crystals hinders practical applications in large-area X-ray detectors.

Purpose of the Study:

• To develop scalable amorphous 0D OMHH films for efficient direct X-ray detection.
• To overcome the size limitations associated with single-crystal 0D OMHHs.
• To investigate the potential of solution-processed amorphous films for advanced detector applications.

Main Methods:

• Synthesized amorphous 0D OMHH films using solution processing by reacting triphenyl(9-phenyl-9H-carbazol-3-yl)phosphonium bromide (TPPCarzBr) with zinc bromide (ZnBr2).
• Fabricated amorphous 0D (TPPCarz)2ZnBr4 films with controlled thickness.
• Characterized the X-ray detection performance of the developed films.

Main Results:

• Successfully produced amorphous 0D (TPPCarz)2ZnBr4 films via facile solution processing.
• Demonstrated efficient molecular sensitization with ZnBr4 2- anions as X-ray absorbers and TPPCarz+ cations as charge transporters.
• Achieved a high X-ray detection sensitivity of 2,165 µC Gyair⁻¹cm⁻² and a low detection limit of 6.01 nGyair s⁻¹.

Conclusions:

• Amorphous 0D OMHH films are a viable and scalable alternative to single crystals for direct X-ray detection.
• The solution-processed amorphous films exhibit excellent X-ray detection performance, including high sensitivity and a low detection limit.
• The enhanced processability of amorphous films makes them highly adaptable for large-area and diverse detector applications.