The electronic and optical properties of amorphous silica with hydrogen defects by ab initio calculations *Project supported by the Science and Technology of Hubei Provincial Department of Education (No. B2017098). (April 2018)

• Record Type: Journal Article
• Authors: Ren, Dahua; Xiang, Baoyan; Hu, Cheng; Qian, Kai; Cheng, Xinlu
• Is Part Of: Journal of semiconductors. Volume 39:Number 4(2018:Apr.)
• Publication Date: 2018-04
• Subjects: amorphous silicon dioxide -- hydrogen defects -- electronic and optical properties -- density functional theory; 2520; Semiconductors -- Periodicals; 621.38152
• DOI: 10.1088/1674-4926/39/4/042002
• Languages: English
• ISSNs: 1674-4926

Abstract

Abstract: Hydrogen can be trapped in the bulk materials in four forms: interstitial molecular H2, interstitial atom H, O − H + (2Si=O–H) +, Si−H − ( ) − to affect the electronic and optical properties of amorphous silica. Therefore, the electronic and optical properties of defect-free and hydrogen defects in amorphous silica were performed within the scheme of density functional theory. Initially, the negative charged states hydrogen defects introduced new defect level between the valence band top and conduction band bottom. However, the neutral and positive charged state hydrogen defects made both the valence band and conduction band transfer to the lower energy. Subsequently, the optical properties such as absorption spectra, conductivity and loss functions were analyzed. It is indicated that the negative hydrogen defects caused the absorption peak ranging from 0 to 2.0 eV while the positive states produced absorption peaks at lower energy and two strong absorption peaks arose at 6.9 and 9.0 eV. However, the neutral hydrogen defects just improved the intensity of absorption spectrum. This may give insights into understanding the mechanism of laser-induced damage for optical materials.