Ultrasensitive and Robust CsPbBr<sub>3</sub> Single-Crystal X-ray Detectors Based on Interface Engineering
Zhilong Chen, Hu Wang, Fenghua Li, Wenqing Zhang, Yuchuan Shao, Shuang Yang
Abstract
Halide lead perovskites have shown great development in recent years for ionizing radiation detection. However, the bias-induced interfacial electrochemical reaction between the perovskite and electrode severely deteriorates detector performance. We report that BCP strongly interacts with Al and constructs a stable Al–BCP chelating interface, resulting in the suppression of a detrimental electrochemical reaction. The fabricated Au/Al/BCP/C 60 /CsPbBr 3 /Au detector shows a low dark current of 3 nA with a stable baseline at an extremely high bias of 100 V (∼100 V mm –1 ). The superior high-bias stability enables a high sensitivity of 7.3 × 10 4 μC Gy air –1 cm –2 at 100 V. Meanwhile, a low detection limit of 15 nGy air s –1 at 40 V is achieved due to the reduced noise. The outstanding performance of our device exceeds that of most advanced detectors based on CsPbBr 3 single crystals. Besides, X-ray imaging with 1 mm spatial resolution is well demonstrated at a low dose rate of 200 nGy air s –1 . The interfacial chelating strategy overcomes the technical limitation of bias-induced instability of perovskite radiation detectors and can be anticipated to operate under an extremely high electrical field.