A comparative study of the structural and optoelectronic properties of Al- and Ga-doped ZnO films deposited by atmospheric pressure plasma jet
Journal
Journal of Alloys and Compounds
Journal Volume
1031
Start Page
180898
ISSN
0925-8388
Date Issued
2025-06-05
Author(s)
Abstract
The high cost of gallium has driven interest in aluminum-doped zinc oxide (AZO) as a cost-effective alternative to gallium-doped zinc oxide (GZO). While prior studies have primarily focused on sputtering methods to compare AZO and GZO, research on non-sputtering techniques remains limited. Our previous works demonstrated favorable optoelectronic properties in GZO films deposited via atmospheric pressure plasma jet (APPJ); however, APPJ-deposited AZO has yet to be explored. In this study, we compare AZO and GZO thin films fabricated by APPJ under ambient conditions. We find that the deposition rate of AZO is approximately twice that of GZO under the same processing parameters, due to differences in droplet size from the ultrasonic generator. By adjusting precursor delivery and working distance (the nozzle-to-substrate gap), we can tune film thickness, morphology, and optoelectronic properties, showcasing APPJ's versatility over sputtering. Despite similar precursor concentrations and film thickness, AZO films exhibit lower carrier concentration (∼1 ×1020 cm–3) and mobility (∼7.5 cm2/Vs) than GZO (∼8 ×1020 cm–3 and ∼15 cm²/Vs), attributed to reduced aluminum incorporation (∼0.4 at% vs. ∼2.2 at% in GZO). Reducing the working distance from 2 mm to 1.5 mm improves both films’ structural integrity and optoelectronic performance (figure of merit increases by 140 % for GZO and 100 % for AZO). However, AZO remains inferior to GZO, highlighting the need for further optimization.
Subjects
Aluminum doped Zinc Oxide (AZO)
Atmospheric pressure plasma jet (APPJ)
Gallium doped Zinc Oxide (GZO)
Transparent conductive oxide (TCO)
Publisher
Elsevier BV
Type
journal article