Correlation of band edge native defect state evolution to bulk mobility changes in ZnO thin films

The evolution of native defect states near conduction band present in ZnO thin films is correlated with the bulk electron density and mobility changes driven by the thermal structure modification. The evolution of band edge electronic structures of ZnO thin films was studied via the spectroscopic detection of empty localized defect states in conduction band (CB) edge and occupied defect states in valence band using spectroscopic ellipsometry and x-ray photoemission spectroscopy. The energy depth of native defect states against CB edge revealed the direct correlation to Hall mobility values for ZnO thin films. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3424790]This work was supported by a Korea Science and Engineering Foundation grant funded by the Ministry of Education, Science, and Technology (No. R11-2005-048-00000-0, SRC/ERC Program, CMPS) and the Information Display R&D Center grant funded by the Ministry of Knowledge Economy (No. F0004061-2009-32, the 21st Century Frontier R&D Program) of the Korean Government. We also acknowledge Professor David Aspnes for the collaboration on SE measurements