Enhanced Carrier Transport in X-Ray Detector Based on Cs3Bi2I9/MXene Composite Wafers

Intrinsically high attenuation of X-rays and excellent optoelectronic properties endow Cs 3 Bi 2 I 9 with great promise for high-performance X-ray detectors. However, preparation of high quality Cs 3 Bi 2 I 9 single crystal with large area and millimeter-thick remains challenging and time-consuming. A size scalable growth technology, a mechanical sintering process, which is applicable for the integration in image detectors is proposed in this work. Compared with the Cs 3 Bi 2 I 9 wafer, the Cs 3 Bi 2 I 9 /MXene composite wafer exhibits higher carrier transfer efficiency and mobility-lifetime product through incorporation of Ti 3 C 2 T x MXene multilayer nanoflakes (MXene nanoflakes). The Cs 3 Bi 2 I 9 /MXene composite wafer X-ray detector shows an excellent linearity of X-ray response, a fast response speed, and a low limit of detection of 231 nGy air s −1 . The sensitivity of 368 µC Gy air −1 cm −2 under 120 V mm −1 is achieved, which is 15.4% enhanced over the Cs 3 Bi 2 I 9 wafer detector. The sensitivity of Cs 3 Bi 2 I 9 /MXene wafer device enhances ≈20–40% at low applied voltage regime. In addition, the Cs 3 Bi 2 I 9 /MXene wafer detector exhibits excellent operational stability after storage for 12 months in ambient air. This work provides an alternative approach for realization of next-generation high-performance perovskite X-ray detectors.