Influence of Ca/Al ratio on properties of amorphous/nanocrystalline Cu-Al-Ca-O thin films
Journal
Journal of the American Ceramic Society
Journal Volume
98
Journal Issue
1
Pages
125-129
Date Issued
2015
Author(s)
Huang B.-W.
Lin G.-W.
Chen P.-Y.
Jiang Y.-H.
Kao P.-K.
Chi C.-T.
Chang H.
Abstract
This article reports the characterization of thin films sputtered from CuAl1-xCaxO targets (x = 0, 0.05, 0.1, 0.15, and 0.2) at room temperature. All films exhibit amorphous/nanocrystalline structures. Their transparency increases slightly with the addition of Ca. Furthermore, the resistivity decreases as the Ca/Al atomic ratio increases. Transmission electron microscopy with energy dispersive spectroscopy mapping indicates that the composition is uniform throughout the films deposited from the highest Ca doping concentration target. Some nanocrystals are present at the top surface of the CuAl0.8Ca0.2O thin film as well as the interface region between the CuAl0.8Ca0.2O thin film and the glass substrate, whereas the interior of the film is pretty amorphous with some embedded nanocrystals. X-ray photoelectron spectroscopy shows that the Cu2+/Cu+ atomic ratio increases with the Ca/Al atomic ratio, indicating the enhancement of p-type conductivity from the nonisovalent Cu-O alloying. ? 2014 The American Ceramic Society.
SDGs
Other Subjects
Atoms; Calcium; Copper; Energy dispersive spectroscopy; Interfaces (materials); Nanocrystals; Semiconducting films; Semiconductor doping; Substrates; Thin films; Transmission electron microscopy; X ray photoelectron spectroscopy; Atomic ratio; Doping concentration; Embedded nanocrystals; Glass substrates; Interface regions; P type conductivity; Room temperature; Thin films-sputtered; Amorphous films
Type
journal article