Enhanced Device Performance of Perovskite Photovoltaics by Magnetic Field‐Aligned Perovskites‐Magnetic Nanoparticles Composite Thin Film

Perovskite photovoltaics have drawn great attention in both academic and industrial sectors in the past decade. To date, impressive device performance has been achieved in state‐of‐the‐art device architectures through morphological manipulation and generic interface engineering. In this study, enhanced device performance of perovskite photovoltaics by magnetic field‐aligned CH 3 NH 3 PbI 3 ‐mixed Fe 3 O 4 magnetic nanoparticles (CH 3 NH 3 PbI 3 :Fe 3 O 4 ) composite thin films is reported. It is found that magnetic field‐aligned CH 3 NH 3 PbI 3 :Fe 3 O 4 composite thin films possess superior film morphology, boosted and balanced charge carrier mobility, and suppressed trap density. Moreover, perovskite photovoltaics by magnetic field‐aligned CH 3 NH 3 PbI 3 :Fe 3 O 4 composite thin films exhibit suppressed charge carrier recombination and shorter charge carrier extraction time. As a result, perovskite solar cells by magnetic field‐aligned CH 3 NH 3 PbI 3 :Fe 3 O 4 composite thin films exhibit 20.23% power conversion efficiency with significantly reduced photocurrent hysteresis. Moreover, perovskite photodetectors by magnetic field‐aligned CH 3 NH 3 PbI 3 :Fe 3 O 4 composite thin films exhibit a photoresponsivity of 858 mA W −1 , a photodetectivity over 10 13 Jones (1 Jones = 1 cm Hz 1/2 W −1 ) and a linear dynamic range over 160 dB at room temperature. All these device performance parameters are significantly better than those by pristine CH 3 NH 3 PbI 3 thin film. Thus, these studies provide a facile way to boost device performance of perovskite photovoltaics.