Large-Area Periodic Organic–Inorganic Hybrid Perovskite Nanopyramid Arrays for High-Performance Photodetector and Image Sensor Applications

The rapid growth of organic–inorganic hybrid perovskite materials (such as methylammonium lead triiodide, MAPbI3) in photoelectric applications has prompted investigations of novel strategies to improve photodetection performance. Although a few surface nanofabrication methods have been applied to texture perovskite thin films to enhance light trapping, it remains challenging to pattern large-area periodic perovskite nanoarrays in a tunable and scalable manner. In this work, we report a facile and low-cost approach to fabricate large-area SiO2/Si nanopyramids arrays through nanosphere lithography. These nanopyramids arrays are used to pattern MAPbI3 thin films. We find that the introduction of nanopyramid arrays enhances the light intensity within the perovskite film, which is confirmed by light absorption tests and optical simulations. As a result, the photodetectors based on MAPbI3 with nanopyramid structures show excellent responsivity of 28.8 ± 1.0 A/W and detectivity of (3.5 ± 0.1) × 1011 Jones at 650 nm. The photoresponse of the photodetector to pulsed light is highly stable and reproducible, with rise and decay times of ∼0.7 and 1.1 ms, respectively. They also have a broader light sensitivity range from ultraviolet to infrared light, i.e., 340 nm to 1100 nm, compared to those without nanostructures. Finally, we demonstrate a prototype image sensor using these photodetector arrays.