title: Comparative studies of Al-doped ZnO and Ga-doped ZnO transparent conducting oxide thin films.
abstract: We have investigated the influences of aluminum and gallium dopants (0 to 2.0 mol%) on zinc oxide (ZnO) thin films regarding crystallization and electrical and optical properties for application in transparent conducting oxide devices. Al- and Ga-doped ZnO thin films were deposited on glass substrates (corning 1737) by sol-gel spin-coating process. As a starting material, AlCl3⋅6H2O, Ga(NO3)2, and Zn(CH3COO)2⋅2H2O were used. A lowest sheet resistance of 3.3 × 103 Ω/□ was obtained for the GZO thin film doped with 1.5 mol% of Ga after post-annealing at 650°C for 60 min in air. All the films showed more than 85% transparency in the visible region. We have studied the structural and microstructural properties as a function of Al and Ga concentrations through X-ray diffraction and scanning electron microscopy analysis. In addition, the optical bandgap and photoluminescence were estimated.
authors.affiliation: Department of Electronic Materials Engineering, Kwangwoon University, Seoul, 139-701, South Korea. jhkoh@kw.ac.kr.
authors.forename: Min-Chul
authors.initials: MC
authors.lastname: Jun
authors.forename: Sang-Uk
authors.initials: SU
authors.lastname: Park
authors.forename: Jung-Hyuk
authors.initials: JH
authors.lastname: Koh