Multiple exciton generation boosting over 100% quantum efficiency photoelectrochemical photodetection

Abstract

Abstract The self-powered photoelectrochemical components themselves featured advancements in operating independently without external supply. Ultimately, due to lack of assistance from the external bias, the photoelectrochemical response is commonly restricted by the deficient photo-quantum efficiency for the absence of carrier multiplication. This work demonstrates a self-powered photoelectrochemical photodetector based on CuOx/AlGaN nanowires with staggered band structure and enhanced built-in potential for efficient exciton extraction. The generated multiple excitons within reach-through CuOx layer could be speedily separated before Auger recombination. This yields a 131.5% external quantum efficiency and 270.6 mA W−1 responsivity at 255 nm. The work confirms the role of multiple exciton generation in photoelectrochemical systems, offering a solution on paving path of advance for self-powered optoelectronics and weak-light UV imaging applications.