Electron transport in Al-Cu co-doped ZnO thin films

Serin T., ATILGAN A., Kara I., Yildiz A.

JOURNAL OF APPLIED PHYSICS, vol.121, no.9, 2017 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 121 Issue: 9
  • Publication Date: 2017
  • Doi Number: 10.1063/1.4977470
  • Journal Name: JOURNAL OF APPLIED PHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Ankara University Affiliated: Yes

Abstract

To investigate the influence of varying Al content on structural, optical, and electrical properties of ZnO thin films, Al-Cu co-doped ZnO thin films with fixed Cu content at 1 wt. % and different Al contents (1, 3, and 5 wt. %) were successfully synthesized on glass substrates using a sol-gel process. The results indicated that the varying Al content affects not only the grain size and band gap but also the electrical conductivity of the films, and a linear relationship was found between the band gap and strain values of the films. The temperature-dependent electrical conductivity data of the films demonstrated that electron transport was mainly controlled by the grain boundaries at intermediate and high temperatures, whereas it was governed by Mott-variable range hopping at low temperatures. Additionally, 3 wt. % Al content improved the electrical conductivity of Al-Cu co-doped ZnO by lowering the trap density and enhancing the hopping probability. Published by AIP Publishing.