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Title: On the variations of optical property and electronic structure in heavily Al-doped ZnO films during double-step growth process

We have investigated the variations of optical property and electronic structure in heavily Al-doped ZnO (AZO) films during the growth process, which were formed by first creating Zn vacancies in O{sub 2}-rich atmosphere and second filling the vacancies with Zn atoms in Zn-vapor atmosphere. After the first step, the high-resistance AZO films have the same optical bandgap with nominally undoped ZnO, indicating that negligible variations in the fundamental bandgap happened to the AZO films although Al atom was incorporated into the ZnO lattice. After the second step, once free electrons were brought into the lattice by Zn-filling, the optical transition energy blueshifts due to the band-filling effect. X-ray absorption fine structure measurements suggest that Zn-filling process decreased the unoccupied states of the conduction band, but not raised the conduction band minimum.
Authors:
; ; ; ; ;  [1] ;  [2]
  1. Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)
  2. Department of Applied Physics, National University of Kaohsiung, Kaohsiung 811, Taiwan (China)
Publication Date:
OSTI Identifier:
22275835
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 2; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION; DOPED MATERIALS; ELECTRONIC STRUCTURE; FINE STRUCTURE; OPTICAL PROPERTIES; THIN FILMS; VACANCIES; X RADIATION; ZINC OXIDES