Response characteristics of MAPbBr3 direct conversion X-ray detectors based on measurements and Monte Carlo simulation

Feng Qin; Rui Zhao; Wei Feng Zhu; Ning Qin Deng; Zhi Wei Jiao; Xian Qiang Tang; Jin Jie Wu

doi:10.1016/j.heliyon.2023.e18875

Response characteristics of MAPbBr₃ direct conversion X-ray detectors based on measurements and Monte Carlo simulation

Heliyon. 2023 Aug 1;9(8):e18875. doi: 10.1016/j.heliyon.2023.e18875. eCollection 2023 Aug.

Authors

Feng Qin^{1

2}, Rui Zhao², Wei Feng Zhu^{2

3}, Ning Qin Deng², Zhi Wei Jiao¹, Xian Qiang Tang^{2

3}, Jin Jie Wu²

Affiliations

¹ China Jiliang University, Hangzhou, 310018, China.
² National Institute of Metrology, Beijing, 100029, China.
³ Chengdu University of Technology, Chengdu, 610059, China.

Abstract

In recent years, higher requirements have been placed on the response characteristics of X-ray detectors in the field of medical diagnostic imaging. Due to this, high sensitivity, high attenuation coefficient and low cost detection materials need to be developed. In this paper, the geometric model of a detector was established by Geant4 code. The absorption efficiency and mass attenuation coefficient of MAPbBr₃ crystals were calculated in the energy range of 30 keV to 100 keV. Compared with the mass attenuation coefficient of the NIST database, the deviation was within 1.39%. The signal charge number and detection sensitivity of the X-ray interaction with the MAPbBr₃ crystal ware calculated. Compared with the CdTe crystal and α-Se, the MAPbBr₃ crystal still had a larger detection sensitivity under a smaller applied electric field, which was approximately 9 times higher than that of α-Se. This result indicated that the detection sensitivity could be greatly improved by using a high atomic number and high charge mobility-lifetime product. Based on the simulation results, the 2 mm thick MAPbBr₃ crystal exhibited the highest detection sensitivity at 60 keV X-rays, which was in agreement with the experimental results.

Keywords: Absorption efficiency; Detection sensitivity; Direct conversion X-ray detectors; Low energy X-ray.