Karatum, OnuralpEren, Guncem OzgunMelikov, RustamzhonOnal, AsimOw-Yang, Cleva W.Sahin, MehmetNizamoglu, Sedat2025-09-252025-09-2520212045-2322https://doi.org/10.1038/s41598-021-82081-yhttps://hdl.handle.net/20.500.12573/4514Melikov, Rustamzhon/0000-0003-2214-7604; Ow-Yang, Cleva W./0000-0002-2909-0957; Sahin, Mehmet/0000-0002-9419-1711; Onal, Asim/0000-0003-3682-6042;Capacitive charge transfer at the electrode/electrolyte interface is a biocompatible mechanism for the stimulation of neurons. Although quantum dots showed their potential for photostimulation device architectures, dominant photoelectrochemical charge transfer combined with heavy-metal content in such architectures hinders their safe use. In this study, we demonstrate heavy-metal-free quantum dot-based nano-heterojunction devices that generate capacitive photoresponse. For that, we formed a novel form of nano-heterojunctions using type-II InP/ZnO/ZnS core/shell/shell quantum dot as the donor and a fullerene derivative of PCBM as the electron acceptor. The reduced electron-hole wavefunction overlap of 0.52 due to type-II band alignment of the quantum dot and the passivation of the trap states indicated by the high photoluminescence quantum yield of 70% led to the domination of photoinduced capacitive charge transfer at an optimum donor-acceptor ratio. This study paves the way toward safe and efficient nanoengineered quantum dot-based next-generation photostimulation devices.eninfo:eu-repo/semantics/openAccessArticle10.1038/s41598-021-82081-y2-s2.0-85100037112