Metal-Free Hydrazinium Halide Perovskitoid Single Crystals for X-ray Detection

Area of Science:

• Materials Science
• Solid-State Physics
• Crystallography

Background:

• Metal-free perovskitoids (MFPs) utilizing hydrazine (N₂H₅⁺) as the B-site component offer unique crystal density and hydrogen bonding.
• MFPs are emerging materials for X-ray detection, but the role of halide composition remains underexplored.

Purpose of the Study:

• To investigate the influence of different halide components on the physical properties and X-ray detection performance of N₂H₅-based MFPs.
• To establish structure-property relationships for optimizing MFP-based X-ray detectors.

Main Methods:

• Fabrication of N₂H₅-based MFP single crystals with varying halide ions (e.g., Br).
• Experimental characterization including crystal structure analysis, band structure determination, and charge transport measurements.
• Device fabrication and performance evaluation for X-ray detection sensitivity and detection limits.

Main Results:

• The tolerance factor and octahedral factor were found to jointly dictate octahedral composition.
• Halide choice significantly impacts octahedral distortion and energy band bending, influencing carrier transport.
• The bromine-based MFP device achieved a high sensitivity of 1284 μC Gy_air^-1 cm^-2 and a low detection limit of 5.62 μGy_air s^-1.

Conclusions:

• Halide selection is crucial for tuning the physical properties and optimizing X-ray detection performance in N₂H₅-based MFPs.
• The superior performance of the Br-based device highlights the potential of tailored halide composition for advanced X-ray detector applications.