Self-powered ultraviolet-blue photodetector based on GaN/double halide perovskite/NiO heterostructure

Abstract: The stability and lead toxicity are two fundamental problems which might impede the application of halide perovskite photodetectors (PDs), and all-inorganic lead-free double halide perovskites might solve the problems simultaneously. Herein, we report that through constructing a p–i–n heterostructure based on a double halide perovskite, Cs₂AgBiBr₆, a self-powered ultraviolet-blue PD was prepared. With a low dark current of 1.89 × 10^–9 A, the device showed a photoresponsivity of 33 mA/W, a specific detectivity of 3.28 × 10¹¹ Jones, an on/off ratio of 1.16 × 10³, and a response speed of 151/215 μs under illumination of 365 nm at zero bias. The device shows good thermal, humidity and oxygen stability. The results indicate that Cs₂AgBiBr₆ might be an ideal active material for developing high-performance short-wavelength PDs with extended spectral response range. Graphical abstract: [Figure not available: see fulltext.].