Structural and functional properties of Al:ZnO thin films grown by Pulsed Laser Deposition at room temperature

• Published in: Thin solid films Vol. 520; no. 14; pp. 4707 - 4711
• Main Authors: Gondoni, P., Ghidelli, M., Di Fonzo, F., Russo, V., Bruno, P., Martí-Rujas, J., Bottani, C.E., Li Bassi, A., Casari, C.S.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2012; Elsevier
• Subjects: Aluminum doped zinc oxide (AZO); Condensed Matter; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electrical conductivity; Electrical properties of specific thin films; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects); Laser deposition; Materials Science; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties; Physics; Pulsed Laser Deposition (PLD); Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Transparent conducting oxide (TCO); Aluminum doped zinc oxide (AZO); Transparent conducting oxide (TCO); Electrical conductivity; Pulsed Laser Deposition (PLD); Optical properties; Transparency; Pressure effects; Hall mobility; Controlled atmospheres; XRD; Thin films; Focusing; Tin oxide; Zinc oxide; Absorption spectra; Carrier mobility; Arsenic additions; Scanning electron microscopy; Vacancies; Zinc additions; Visible spectra; Pulsed laser deposition; Indium oxide; Optical density; Electrical measurement; Aluminium additions; Laser ablation technique; Transparent material; Defect formation
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2011.10.072

Current research on transparent conductive oxides (TCOs) is focusing on indium-free TCOs, such as Al-doped ZnO (AZO), as an alternative to indium–tin oxide. In this work, AZO thin films were grown by Pulsed Laser Deposition at room temperature in oxygen atmosphere. The O2 pressure was varied from 0.01Pa to 10Pa, highlighting the effects of defect formation and oxygen vacancies on the film properties. Structural properties were characterized by X-ray diffraction and Scanning Electron Microscopy, while functional properties were characterized by measurement of electrical conductivity, Hall mobility, carrier density and optical transmission. At an optimal deposition pressure of 2Pa, optical transparency in the visible range and minimum resistivity (4.5∙10−4Ωcm) were found, comparable to state-of-the-art TCOs. Mean value of visible transparency was shown to increase with increasing pressure, up to 88% at a deposition pressure of 10Pa.