Year: 2018
Type: article
Abstract: We present density functional theory (DFT) calculations of oxygen and silver defects in a crystalline model of amorphous Ge2Se3. We studied defects arising from atomic oxygen and dioxygen, as well as interstitial silver and silver displacing germanium, following Campbell's conjecture on the mechanism of dendrite formation. For oxygen defect concentrations below 2%, we show that O2 dissociates in Ge2Se3, oxygen atoms are immobile, and oxygen atoms do not cluster. Within this model, the most preferred oxygen defect in intrinsic Ge2Se3 is Ge-O-Ge bridge. We conclude that oxygen defects will not severely alter the electrical properties of Ge2Se3. Our results on silver defects in Ge2Se3 agree with and extend previous work using a similar model; the two most preferred silver defect types are intralayer silver interstitial and silver displacement of germanium. We also studied the interaction between silver defects and the most preferred oxygen defect. We learned that discounting the highest defect concentrations, oxygen defects will not severely change the behavior of silver defects in Ge2Se3, but it will inhibit the formation of Ag-Ge dimers.
Author: Jau-Tzuoo Chen
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2945962559