Effect of Ge Concentration in GexSe1-x Chalcogenide Glass on the Electronic Structures and the Characteristics of Ovonic Threshold Switching (OTS) Devices

Abstract

We studied GexSe1-x for the potential application in the Ovonic Threshold Switching (OTS) device. We found that, as Ge concentration increased, the thermal stability was deteriorated while the device performances were improved. In addition, using Spectroscopic Ellipsometry (SE) technique, the energy gap (E-g) and the Urbach energy (E-U) were found to show non- monotonic dependences, with their minimum of about 1.0 eV of E-g for Ge0.6Se0.4 and 40 meV of E-U for Ge0.5Se0.5. These changes are consistent with the changes in device characteristics, which might be explained in terms of the change in the number of Se-Se bondings. (c) 2013 The Electrochemical Society. All rights reserved.