Band alignment determination of ZnO/PbSe heterostructure interfaces by synchrotron radiation photoelectron spectroscopy

Band offsets at ZnO/PbSe heterostructure interfaces are determined by synchrotron radiation photoelectron spectroscopy. A type-I band alignment with the valence band offset (VBO) ?EV?=?0.73?eV and conduction band offset (CBO) ?EC?=?2.36?eV is concluded for ZnO/PbSe film heterojunctions. The approach is extended to ZnO/PbSe nanocrystal (NC) heterojunctions, which reveals that band alignment can be adjusted via varying the dot size and a type-II alignment is formed when the dot size is ?5?nm. The small conduction band offset of the ZnO/PbSe film heterojunction and the tunable band alignment of the ZnO/PbSe NCs heterojunction with different crystal sizes shall benefit the design and fabrication of improved optoelectronic devices.