Interfacial charge transfer between CsPbBr <sub/>3</sub> quantum dots and ITO nanoparticles revealed by single-dot photoluminescence spectroscopy

摘要： The interfacial charge transfer between single CsPbBr3 perovskite quantum dots (QDs) and indium tin oxide (ITO) is investigated by single-dot photoluminescence spectroscopy. It is found that when the Fermi level of single perovskite QDs aligns with that of ITO nanoparticles, the QD surface cannot be charged by the ITO through interfacial electron transfer. Therefore, the QD/ITO system with Fermi level alignments can exclude exciton nonradiative recombination processes involving the additional surface electrons, such as the exciton Auger recombination and the valence band hole transfer processes. Hence the photovoltaic devices based on perovskite QD/ITO system with the Fermi level alignments have the improved photoelectric conversion efficiency.