Narrowband Perovskite Photodetector-Based Image Array for Potential Application in Artificial Vision

Abstract

Image sensor arrays are widely used in digital cameras, smartphones, and biorobots. However, most commercial image arrays rely on the dichroic prisms or a set of interference filters to distinguish characteristic color spectrum, which significantly increases the cost and fabrication processing complexity. In this work, an ultranarrow response photodetector with full-width at half-maximum being ∼12 nm and specific detectivity over 10¹¹ Jones at 545 nm are successfully achieved in CsPbBr₃ polycrystalline films using freeze-drying casting method to adjust the surface-charge recombination. To our best knowledge, this is the narrowest spectrum response for perovskite photodetectors in the visible light waveband. More importantly, a series of narrowband photodetectors are developed to enhance diverse selectivity for target signals covering from blue light to red light via bandgap tuning in CsPbX₃ by tailoring the halide component. Finally, an integrated sensing array with CsPbX₃ (X = Cl, Br, I) narrowband photodetectors acting as color recognition cones is constructed, which presents clear color and shape recognition paving the way for commercialization of perovskite photodetector in artificial vision.