作者：Wei Qin, Wen-Cai Lu, Lin-Hua Xia, Li-Zhen Zhao, Qing-Jun Zang, C. Z. Wang
關(guān)鍵字：Si172 QDs; hydrogenated Si172 QDs; optical properites;
論文來源：期刊
具體來源：Nanoscale
發(fā)表時間：2015年
The structures and optical properties of silicon quantum dots (QDs) have long been studied. Exploring the growth pattern of silicon crystal is challenging due to the competitions among various structural motifs. Here, about 1.7 ~ 1.9 nm silicon QDs (Si172 QDs) have been unbiased searched by genetic algorithm (GA) combined with a tight-binding molecular dynamics (TBMD) method. The optical properties of the bare and hydrogenated Si172 QDs have been studied using the time-dependent density functional theory (TD-DFT) calculations. We found that at the inner part of the Si172 QDs, a silicon crystal has been formed. Comparing with the bare Si172 QDs, the maximum absorption peaks of the hydrogenated Si172 QDs have shifted from the near infrared region to the visible region or the ultraviolet region.