Simultaneous enhancement of electrical conductivity, uniformity, and near-infrared transmittance via laser annealing on ZnO:Ga films deposited by atmospheric pressure plasma jet
Journal
Journal of Alloys and Compounds
Journal Volume
857
Date Issued
2021
Author(s)
Abstract
Atmospheric pressure plasma jet (APPJ) has been used to deposit transparent conductive oxides (TCO) in ambient conditions with optoelectronic properties comparable to vacuum-based techniques. However, APPJ-deposited TCO films tend to exhibit a relatively low electrical uniformity, and it is still challenging to improve TCO's conductivity without compromising the near-infrared (NIR) transmittance. Here, we demonstrate that continuous CO2 laser annealing can simultaneously enhance the electrical conductivity, uniformity, and NIR transmittance of Ga-doped zinc oxides (GZO) prepared by APPJ on 5 × 5 cm2 glasses. GZO films annealed with a laser power of 4.35 W achieve a low resistivity (5.5 × 10?4 Ω cm ? 6.0 × 10?4 Ω cm), a high Hall mobility (14.5 cm2 V?1 s?1 ? 15.5 cm2 V?1 s?1), a low non-uniformity in resistivity (3% ? 5%) and a high transmittance in the visible spectra (>80%, including 10% loss due to the glass substrate). The transmittance in the NIR spectra increases from 52.6% to 61.4% (+16%), and may be further improved by reducing the carrier concentration (6.8 × 1021 cm?3 ? 7.6 × 1021 cm?3 in this study). The enhancement may be attributed to the reduction of Ga–O clusters, which act as barrier traps that degrade the carrier mobility. Our findings may also be applied to other scanning-based deposition methods such as spray pyrolysis. ? 2020 Elsevier B.V.
Subjects
Atmospheric pressure; Carbon dioxide lasers; Carrier concentration; Electric conductivity; Gallium compounds; Glass; Hall mobility; Hole mobility; II-VI semiconductors; Infrared devices; Oxide minerals; Plasma jets; Spray pyrolysis; Substrates; Zinc oxide; Ambient conditions; Atmospheric pressure plasma jets; Electrical conductivity; Electrical uniformity; Ga-doped zinc oxides; Near-infrared transmittances; Optoelectronic properties; Transparent conductive oxides; Annealing
SDGs
Type
journal article