Interlayer-Assisted Growth of Si-Based All-Inorganic Perovskite Films via Chemical Vapor Deposition for Sensitive and Stable X-ray Detection

All-inorganic perovskites are considered as preferred materials for nextgeneration X-ray detectors. However, preparing high-quality thick films by traditional solution-based methods remains challenging due to the low solubility of the precursors. In this work, chemical vapor deposition technology is employed to grow Si-based all-inorganic cesium-lead-bromide perovskite thick films. By introducing a SnO2 nanocrystal interlayer onto the Si substrate to facilitate the heterogeneous nucleation of the perovskite, we are able to grow high-quality films with a smooth surface and compact grains at a relatively low substrate temperature of 260 degrees C. The resultant X-ray detectors exhibit a decent sensitivity of 2930 mu C Gyair -1 cm-2, a small dark current density of 1.5 nA cm-2, and a low detection limit of 120 nGyair s-1. Moreover, the devices show excellent biasing stability with a record small baseline drift of 4.6 x 10-9 nA cm-1 s-1 V-1 under a large electric field of 1100 V/cm among all perovskite polycrystalline film-based detectors ever reported.