Effect of Post-Annealing on Structural and Electrical Properties of ZnO:In FilmsSupported by the National Natural Science Foundation of China under Grant Nos 51472038 and 51502030, the Natural Science Foundation of Chongqing City under Grant Nos CSTC2016jcyjA and 2018jcyjA2923, the Education Commission of Chongqing under Grant Nos KJ1500319, 1501112 and KJ1600314, and the PhD Scientific Research Fund under Grant No 16XlB002

• Published in: Chinese physics letters 2019-04, Vol.36 (4)
• Main Authors: Qin, Guo-Ping, Zhang, Hong, Ruan, Hai-Bo, Wang, Jiang, Wang, Dong, Kong, Chun-Yang
• Format: Article
• Language: English
• ISSN: 0256-307X
• DOI: 10.1088/0256-307X/36/4/047301

Indium-doped ZnO (ZnO:In) films are deposited on quartz substrates by rf magnetron sputtering. The effects of post-annealing on structural, electrical, optical and Raman properties are investigated by x-ray diffraction, Raman scattering, Hall measurement and first-principles calculation. The results indicate that all of the ZnO:In films have excellent crystallinity with a preferred ZnO (002) orientation. It is found that the incorporation of In can dramatically increase the intensity of the 274 cm−1 Raman mode. However, both post-annealing treatment and increasing O2 partial pressure in the process of preparing thin films can reduce the intensity of the 274 cm−1 mode or even eliminate it, and relax compressive stress of the ZnO:In film judged by analyzing the shifts of the (002) Bragg peaks and E2 (high) mode. Finally, the origin of the 274 cm−1 mode is inferred to be the vibration of Zn interstitial (Zni) defects, which play a crucial role in the high electron concentration and low resistivity of ZnO:In films annealed in an appropriate temperature range (450-600°C).