High-Detectivity Perovskite Photodetector Using Combustion-Processed NiO _x as p-Type Buffer Layer

We fabricated a photodetector device consisting of ITO/NiO _x /Perovskite/PC₆₀BM/BCP/Ag. The NiO _x layer was deposited using the sol–gel and combustion processes. Combustion-processed NiO _x films have advantages such as low annealing temperature, improved perovskite film quality, and better photodetector performance compared to the sol–gel processed NiO _x film. The improved film quality, improved charge transfer, and reduced dark current of the device using combustion-processed NiO _x film were investigated by measuring the current–voltage characteristics, transient photocurrent, and impedance analysis. The photodetector using the combustion-processed NiO _x achieved a high detectivity of 1.20×10¹³ Jones and bandwidth of over 2 MHz at -0.1 V and 550 nm.