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

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.