Gradient Doping Triggers Flexo-Pyroelectric Effects toward Self-Powered Broadband Photodetection and Smart Recognition

and an external quantum efficiency exceeding 100%. Notably, leveraging its nonlinear optical response, the detector demonstrates substantial potential for smart sensing, as evidenced by its capability for the quantitative identification of environmental pollutants. This work not only presents a novel pathway for harnessing flexoelectricity in functional optoelectronics but also provides a general design principle for developing next-generation intelligent self-powered sensing systems.