Stabilize the Interface of Perovskite Electronics for Sensing

Metal halide perovskite semiconductors are emerging low-cost materials for photovoltaics, light emitting devices and detectors. Because of the inclusion of high atomic numbered elements, perovskites are demonstrated for high efficiency X-ray sensing surpassing the performance of the detectors made with classical semiconductors. However, among all these applications, the operational stability has been a major challenge. One key cause is the interface degradation between the perovskite material and the electrode. In this talk, I will discuss two alternative interface materials to stabilize the perovskite detectors’ performances. Firstly, we investigate graphene as an electrode for perovskite X-ray detector. We found that building perovskite on monolayer graphene form a charge injection interface that exhibited high sensitivities. Interestingly, The full device can be recycled by removing perovskite with solution method, and the graphene layer is fully recovered for the next fabrication. Secondly, we employed GaN as an n-type electrode for perovskite diode. It can efficiently collect the generated electron from the perovskite absorbing layer. And the GaN is a chemically robust interface for perovskite, device made over GaN remained stable over 200 cycles of X-ray irradiation without sign of degradation. In summary, finding robust electrode and interface material is the key to stabilize the perovskite devices.