Structural, Electrical and Optical Properties of ZnO Thin Films Co-doped with Titanium and Hydrogen Prepared by RF Magnetron Sputtering with Different Substrate Temperatures | Chapter 4 | Current Innovations in Chemical and Materials Sciences Vol. 6

Transparent conducting oxides (TCOs) exhibit a distinctive blend of exceptional transparency and electronic conductivity, making them pivotal in diverse optoelectronic devices. Among these, indium tin oxide is widely used, while zinc oxide (ZnO) emerges as a promising TCO material with substantial commercial applications. This research endeavors to enhance the optoelectronic characteristics of titanium and hydrogen co-doped ZnO (TZO:H) thin films by manipulating the substrate temperature during deposition and introducing hydrogen gas. TZO:H thin films were fabricated on glass substrates via radio-frequency magnetron sputtering, utilizing a sputtering target composed of 1.5 wt% TiO2-doped ZnO. Varied H2/(Ar+H2) flow ratios (RH = 0–15%) and substrate temperatures (TS = RT–300°C) were employed. The structural, electrical, and optical properties of the TZO:H thin films were thoroughly examined through X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), Hall-effect measurements, UV/Visible/IR spectrophotometry, and X-ray photoelectron spectroscopy. XRD analysis revealed that all TZO:H films exhibited a hexagonal wurtzite structure with a predominant (002) orientation. The average transmittance in the visible region exhibited a decline with increasing RH in RT-deposited films, whereas it remained relatively stable at different RH levels for films deposited at 300°C. The resistivity of TZO:H films exhibited a strong dependence on both TS and RH. Through optimization of substrate temperature and hydrogen flow rate, the minimum resistivity of the TZO:H thin film experienced a notable reduction by over two orders of magnitude to 9´10-4 Ω×cm.

Author(s) Details:

Fang-Hsing Wang,
Department of Electrical Engineering, Graduate Institute of Optoelectronic Engineering, National Chung Hsing University, Taichung, 402202, Taiwan.

Jen-Chi Chao,
Department of Electrical Engineering, Graduate Institute of Optoelectronic Engineering, National Chung Hsing University, Taichung, 402202, Taiwan.

Han-Wen Liu,
Department of Electrical Engineering, Graduate Institute of Optoelectronic Engineering, National Chung Hsing University, Taichung, 402202, Taiwan.

Tsung-Kuei Kang,
Department of Electronic Engineering, Feng-Chia University, Taichung 407202, Taiwan.

Please see the link here: https://stm.bookpi.org/CICMS-V6/article/view/13528