Reinforcing Photogenerated Carrier Extraction of Environment‐Friendly InP/ZnSeS Quantum Dots for High‐Performing Photoelectrochemical Photodetection and Solar Energy Conversion

Abstract Colloidal InP/ZnSeS‐based quantum dots (QDs) are considered promising building blocks for light‐emitting devices due to their environmental friendliness, high quantum yield (QY), and narrow emission. However, the intrinsic type‐I band structure severely hinders potential photoelectrochemical (PEC) applications requiring efficient photoexcited carrier separation and transfer. In this study, the optoelectronic properties of InP/ZnSeS QDs are tailored by introducing Al dopants in the ZnSeS layer, which concurrently passivate the surface defects and act as shallow donor states for suppressed non‐radiative recombination and improved charge extraction efficiency. Consequently, as‐fabricated InP/ZnSeS:Al QDs‐based PEC‐type photodetector exhibited a high detectivity up to 10 11 Jones and a remarkable responsivity of 0.66 A W −1 at 600 nm even under self‐powered condition (0V bias). In addition, as‐prepared InP/ZnSeS:Al QDs‐based photoanode can be alternatively used for PEC hydrogen generation, showing an H 2 production rate of 73.7 µmol cm −2 h −1 under 1 sun illumination (AM 1.5G, 100 mW cm −2 ). The results offer a prospective strategy for optimizing eco‐friendly QDs for high‐performance multifunctional light detection/conversion devices.