Noncontact Gesture Control Using Nested Multi‐Periodic Grating Modulated Perovskite Near‐Infrared Photodetector

ABSTRACT Miniaturized photodetectors (PDs) with high sensitivity and large dynamic range hold substantial promise for noncontact gesture control. However, their reliance on external power sources, limited anti‐interference capability in intricate environments, and the cost‐performance trade‐offs of high‐performance designs hinder broader application. Here, we present a solution‐processed, self‐powered tin‐lead perovskite near‐infrared PD modulated by a nested multi‐periodic grating for a real‐time noncontact gesture control system. The grating structure, directly fabricated via single‐step femtosecond laser direct writing, synergistically combines micron‐scale diffraction and subwavelength anti‐reflection to prolong the effective optical path, enhancing light trapping and absorption. The PD exhibits a peak external quantum efficiency of 92.1%, responsivity of 0.49 A W −1 , ultrafast rise/fall times of 390/501 ns, linear dynamic range of 147 dB, and weak angular dependence (< 9% variation over 0–30°) when operated at 0 V bias. Enabled by a one‐dimensional residual network, the PD translates photocurrents into vehicle commands with high accuracy under low‐light radiation and foggy conditions, demonstrating its potential for self‐powered, flexible, intelligent, and noncontact human–machine interaction in complex environments.