Investigation of the Structural, Electrical, and Optical Properties of the Nano-Scale GZO Thin Films on Glass and Flexible Polyimide Substrates

Fang-Hsing Wang; Kun-Neng Chen; Chao-Ming Hsu; Min-Chu Liu; Cheng-Fu Yang

doi:10.3390/nano6050088

Investigation of the Structural, Electrical, and Optical Properties of the Nano-Scale GZO Thin Films on Glass and Flexible Polyimide Substrates

Nanomaterials (Basel). 2016 May 10;6(5):88. doi: 10.3390/nano6050088.

Authors

Fang-Hsing Wang¹, Kun-Neng Chen², Chao-Ming Hsu³, Min-Chu Liu⁴, Cheng-Fu Yang⁵

Affiliations

¹ Department of Electrical Engineering and Graduate Institute of Optoelectronic Engineering, National Chung Hsing University, Taichung 402, Taiwan. fansen@dragon.nchu.edu.tw.
² Department of Electrical Engineering, Kun-Shan University, Tainan 710, Taiwan. knchen@mail.ksu.edu.tw.
³ Department of Mechanical Engineering, National Kaohsiung University of Applied Science, Kaohsiung 807, Taiwan. jammy@kuas.edu.tw.
⁴ Department of Electrical Engineering and Graduate Institute of Optoelectronic Engineering, National Chung Hsing University, Taichung 402, Taiwan. stmike18@yahoo.com.tw.
⁵ Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 81141, Taiwan. cfyang@nuk.edu.tw.

Abstract

In this study, Ga₂O₃-doped ZnO (GZO) thin films were deposited on glass and flexible polyimide (PI) substrates at room temperature (300 K), 373 K, and 473 K by the radio frequency (RF) magnetron sputtering method. After finding the deposition rate, all the GZO thin films with a nano-scale thickness of about 150 ± 10 nm were controlled by the deposition time. X-ray diffraction patterns indicated that the GZO thin films were not amorphous and all exhibited the (002) peak, and field emission scanning electron microscopy showed that only nano-scale particles were observed. The dependences of the structural, electrical, and optical properties of the GZO thin films on different deposition temperatures and substrates were investigated. X-ray photoemission spectroscopy (XPS) was used to measure the elemental composition at the chemical and electronic states of the GZO thin films deposited on different substrates, which could be used to clarify the mechanism of difference in electrical properties of the GZO thin films. In this study, the XPS binding energy spectra of Ga2p_3/2 and Ga2p_1/2 peaks, Zn2p_3/2 and Zn2p_1/2 peaks, the Ga3d peak, and O₁_s peaks for GZO thin films on glass and PI substrates were well compared.

Keywords: Ga2O3-doped ZnO (GZO) thin film; X-ray photoelectron spectroscopy (XPS); glass; polyimide (PI).