中国物理B ›› 2010, Vol. 19 ›› Issue (7): 76101-076101.doi: 10.1088/1674-1056/19/7/076101

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Structural and electrical properties of single crystalline and bi-crystalline ZnO thin films grown by molecular beam epitaxy

徐明祥1, 邹文琴2, 张凤鸣2, 路忠林3   

  1. (1)Department of Physics, Southeast University, Nanjing 210096, China; (2)National Laboratory of Solid State Microstructure, and Department of Physics, Nanjing University, Nanjing 210093, China; (3)National Laboratory of Solid State Microstructure, and Department of Physics, Nanjing University, Nanjing 210093, China;Physics Department and Institute of Innovations and Advanced Studies (IIAS), National Cheng Kung University, Tainan 701, China;Departme
  • 收稿日期:2009-09-08 出版日期:2010-07-15 发布日期:2010-07-15
  • 基金资助:
    Project partially supported by the National Natural Science Foundation of China (Grant No. 10804017), the Natural Science Foundation of Jiangsu Province of China (Grant No. BK2007118), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20070286037), the Cyanine-Project Foundation of Jiangsu Province of China (Grant No. 1107020060), the Foundation for Climax Talents Plan in Six-Big Fields of Jiangsu Province of China (Grant No. 1107020070), and the New Century Excellent Talents in University (Grant No. NCET-05-0452).

Structural and electrical properties of single crystalline and bi-crystalline ZnO thin films grown by molecular beam epitaxy

Lu Zhong-Lin(路忠林)a)b)c)†, Zou Wen-Qin(邹文琴) a), Xu Ming-Xiang(徐明祥)c), and Zhang Feng-Ming(张凤鸣)a)   

  1. a National Laboratory of Solid State Microstructure, and Department of Physics, Nanjing University, Nanjing 210093, China; b Physics Department and Institute of Innovations and Advanced Studies (IIAS), National Cheng Kung University, Tainan 701, China; c Department of Physics, Southeast University, Nanjing 210096, China
  • Received:2009-09-08 Online:2010-07-15 Published:2010-07-15
  • Supported by:
    Project partially supported by the National Natural Science Foundation of China (Grant No. 10804017), the Natural Science Foundation of Jiangsu Province of China (Grant No. BK2007118), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20070286037), the Cyanine-Project Foundation of Jiangsu Province of China (Grant No. 1107020060), the Foundation for Climax Talents Plan in Six-Big Fields of Jiangsu Province of China (Grant No. 1107020070), and the New Century Excellent Talents in University (Grant No. NCET-05-0452).

摘要: C-oriented ZnO epitaxial thin films are grown separately on the a-plane and c-plane sapphire substrates by using a molecular-beam epitaxy technique. In contrast to single crystalline ZnO films grown on a-plane sapphire, the films grown on c-plane sapphire are found to be bi-crystalline; some domains have a 30o rotation to reduce the large mismatch between the film and the substrate. The presence of these rotation domains in the bi-crystalline ZnO thin film causes much more carrier scatterings at the boundaries, leading to much lower mobility and smaller mean free path of the mobile carriers than those of the single crystalline one. In addition, the complex impedance spectra are also studied to identify relaxation mechanisms due to the domains and/or domain boundaries in both the single crystalline and bi-crystalline ZnO thin films.

Abstract: C-oriented ZnO epitaxial thin films are grown separately on the a-plane and c-plane sapphire substrates by using a molecular-beam epitaxy technique. In contrast to single crystalline ZnO films grown on a-plane sapphire, the films grown on c-plane sapphire are found to be bi-crystalline; some domains have a 30$^\circ$ rotation to reduce the large mismatch between the film and the substrate. The presence of these rotation domains in the bi-crystalline ZnO thin film causes much more carrier scatterings at the boundaries, leading to much lower mobility and smaller mean free path of the mobile carriers than those of the single crystalline one. In addition, the complex impedance spectra are also studied to identify relaxation mechanisms due to the domains and/or domain boundaries in both the single crystalline and bi-crystalline ZnO thin films.

Key words: ZnO, grain boundaries, complex impedance spectra, single crystalline and bi-crystalline thin films

中图分类号:  (Nucleation and growth)

  • 68.55.A-
73.61.Ga (II-VI semiconductors) 68.55.-a (Thin film structure and morphology) 81.15.Hi (Molecular, atomic, ion, and chemical beam epitaxy)