Band alignment determination of ZnO/PbSe heterostructure interfaces by synchrotron radiation photoelectron spectroscopy
1 Department of Physics, State Key Laboratory of Silicon Materials, Zhejiang University Hangzhou, Zhejiang 310027, PRC
2 National Synchrotron Radiation Laboratory, University of Science and Technology of China Hefei, Anhui 230029, PRC
Received: 3 May 2012
Accepted: 12 July 2012
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) ΔEV = 0.73 eV and conduction band offset (CBO) ΔEC = 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.
PACS: 73.20.-r – Electron states at surfaces and interfaces / 73.40.-c – Electronic transport in interface structures / 73.90.+f – Other topics in electronic structure and electrical properties of surfaces, interfaces, thin films, and low-dimensional structures (Restricted to new topics in section 73)
© EPLA, 2012