Curviform surface breaks the symmetrical shape of silicon quantum dots on which some bonds can produce localized electronic states in band gap. The calculation results show that the bonding energy and electronic states of silicon quantum dots are different on various curved surfaces, for example, an Si-O-Si bridge bond on curved surface provides the localized levels in band gap and its bonding energy is shallower than that on facet. The red-shifting of PL spectrum on smaller silicon quantum dots can be explained by curved surface effect. Experiments demonstrate that silicon quantum dots are activated for emission due to the localized levels formed in the band gap.

 

Publication name	ACTA PHYSICA SINICA　Volume: 62　 Issue: 8　　 Article Number: 084205　Published: 2013
Author(s)	Huang Wei-Qi; Zhou Nian-Jie; Yin Jun; Miao Xin-Jian; Huang Zhong-Mei; Chen Han-Qiong; Su Qin; Liu Shi-Rong; Qin Chao-Jian
Corresponding author	HUANG Weiqi  WQHuang2001@yahoo.com  Guizhou Univ, Inst Nanophoton Phys, Key Lab Photoelect Technol & Applicat, Guiyang 550025, Peoples R China.
Author(s) from IGCAS	LIU Shirong, QIN Chaojian