Perovskite-Based Facile NiO/CH₃NH₃PbI₃ Heterojunction Self-Powered Broadband Photodetector

Perovskite light absorbers have drawn attention worldwide for optoelectronic devices due to their solution-processable photovoltaic properties, high carrier mobility, broad spectral range, and integration with a wide range of substrates, etc. A facile NiO/CH3NH3PbI3 heterojunction was fabricated in an ambient environment for self-powered and high-performance photodetector (PD) application. The self-powered PD showed a high responsivity of 33.39 mA/W for UV light and 5.79 mA/W for white light at zero bias, which further increases up to 28.6 A/W for UV light and 29.2 A/W for white light at +1 V. Subsequently, the detectivity for an entire UV and visible spectrum was observed to be above 1010 Jones at zero bias. Interestingly, the stability study for PDs in the air up to 38 days revealed the highest photoresponsivity of 40.56 mA/W at zero bias. This enhancement is attributed to the intrinsic modification within metal halide perovskites that lead to optimized PbI2 content. Additionally, a systematic study of X-ray diffraction patterns at an interval of days revealed the presence of PbI2 content. Further, the photodetection ability was retained for up to 58 days with a decrease in light current without encapsulation. Our results indicate that a NiO/CH3NH3PbI3 heterojunction-based PD paves the way for ambient friendly, high-performance, self-powered, stable optoelectronic applications.