The impact of defect states in ZnO quantum dot on energy level alignment

Abstract

ZnO nanoparticles (NP) exhibit advantageous properties for quantum dot based electronic applications such as widely tunable band-gap and high enough conductivity to be used for an electron transport layer. According to the recent theoretical report, however, there exist unexpected defective states in ZnO that possibly affect the electrical and optical properties. In this work, we demonstrate the comprehensive understandings of the impact of defect states in ZnO-NP on their energy level alignments by using photoluminescence and photoelectron spectroscopy.