Enhanced Vis-NIR light absorption and thickness effect of Mo-modified SnO2 thin films: A first principle calculation study
Jianqiao Liu, Haipeng Zhang, Yilin Li, Haoran Shen, Yang Ding, Ningning Su, Liang Shao, Guohua Jin, Zhaoxia Zhai, Ce Fu, Qianru Zhang
Abstract
The thickness effect on ultraviolet, visible and near-infrared (UV–Vis-NIR) light absorption of Mo-modified tin oxide (SnO2) thin films is investigated by the first principle calculation based on the density functional theory. The electronic structures and optical properties of the pristine, defective, Mo-doped and Mon (n = 1, 2, 3, 4) cluster adsorbed SnO2 (1 1 0) surfaces with film thickness from 0.594 to 3.273 nm are discussed. The results show that the pristine SnO2 semiconductor thin films can hardly absorb the Vis-NIR light. The absorption peaks in the Vis-NIR light region of the defective SnO2 (1 1 0) surface increase with the film thickness. The Vis-NIR light absorption of SnO2 is significantly enhanced by Mo modification. Mon cluster adsorption on SnO2 makes the greatest enhancement in Vis-NIR light absorption. The surface modification of Mo is concluded to be a promising route for SnO2 semiconductor thin film as a photocatalyst under Vis-NIR light irradiation.