Addressing the Voltage Induced Instability Problem of Perovskite Semiconductor Detectors

Perovskite-based solid-state radiation detectors have delivered impressive performances, but the electrical field induced instability has been a major detriment for the further development. Here, we identify the voltage-induced instability is directly tied to the humidity levels. A higher humidity elicits a hysteresis in the current-voltage curve and lowers the breakdown voltage. We further add a fluorinated phenylethylamine iodide (5F-PEAI) barrier layer on the perovskite, which protects the device against voltage damage. Photoluminescence maps identify the ion migration and degradation can be suppressed by 5F-PEAI. Quantum chemical simulations corroborate experimental results by revealing high energy barrier for water penetrating the 5F-PEAI layer with enhancing stability of halide perovskite under humid condition. Using a treated device, we demonstrate high X-ray sensitivities approaching 1000 μC/(Gy_air·cm²) under high biases. Our work provides a mechanistic understanding on the voltage instability of 2D perovskite detectors and provides a viable solution toward robust detector development.