Interface enhancement effect: SnO2/CsPbBr3 hetero-junction for improve nuclear radiation detection performance and stability

The CsPbBr3 single crystal detector emerges as a highly promising candidate among semiconductor nuclear radiation detectors, which exhibits an extensive potential application across a multitude of critical domains, particularly in nuclear physics, nuclear energy, nuclear medicine, etc. However, the polarization problem has limited the application and development of CsPbBr3 detectors and has even posed a significant hindrance to their practical implementation. In this paper, a pre-designed SnO2/CsPbBr3 hetero-junction was meticulously engineered at the interface of the Ti/CsPbBr3/Ti detector, aiming to solve the polarization problem. This paper investigates the effects of the SnO2/CsPbBr3 hetero-junction on the electrical characteristics, detection performance, and long-term stability of the detector. The final results demonstrated that the SnO2/CsPbBr3 hetero-junction had multiple beneficial effects on the CsPbBr3 detector. On the one hand, the SnO2/CsPbBr3 hetero-junction exhibited superior electron extraction efficiency when compared to the Ti/CsPbBr3 interface. On the other hand, the SnO2 layer played a crucial role in preventing the migration of ions from the CsPbBr3 crystal to the interface, as well as in blocking the permeation of atmospheric and moisture elements from the detector surface to the interface. Consequently, the SnO2/CsPbBr3 hetero-junction detector exhibited superior detection performance and enhanced long-stability when compared to the Ti/CsPbBr3/Ti detector. After the interface enhancement, the SnO2/CsPbBr3 hetero-junction detector achieved an improved energy resolution of 13.59% at an electric field of 6000 V/cm and maintained a stable energy resolution of approximately 24 ± 5% at 3000 V/cm for over 12 h. The study of the SnO2/CsPbBr3 hetero-junction detector in this work provided a new perspective for enhancing the detection performance and ensuring the long-term stability of CsPbBr3-based detectors.