中国物理B ›› 2013, Vol. 22 ›› Issue (6): 64207-064207.doi: 10.1088/1674-1056/22/6/064207

• ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS • 上一篇    下一篇

Electronic states and shape of silicon quantum dots

黄伟其, 苗信建, 黄忠梅, 陈汉琼, 苏琴   

  1. Institute of Nanophotonic Physics, Key Laboratory of Photoelectron Technology and Application, Guizhou University, Guiyang 550025, China
  • 收稿日期:2012-08-14 修回日期:2012-10-10 出版日期:2013-05-01 发布日期:2013-05-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 60966002 and 11264007) and the National Key Laboratory of Surface Physics in Fudan University, China.

Electronic states and shape of silicon quantum dots

Huang Wei-Qi (黄伟其), Miao Xing-Jian (苗信建), Huang Zhong-Mei (黄忠梅), Cheng Han-Qiong (陈汉琼), Shu Qin (苏琴)   

  1. Institute of Nanophotonic Physics, Key Laboratory of Photoelectron Technology and Application, Guizhou University, Guiyang 550025, China
  • Received:2012-08-14 Revised:2012-10-10 Online:2013-05-01 Published:2013-05-01
  • Contact: Huang Wei-Qi E-mail:WQHuang2001@yahoo.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 60966002 and 11264007) and the National Key Laboratory of Surface Physics in Fudan University, China.

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

关键词: Si quantum dots, curved surface effect, surface bonds, localized levels

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

Key words: Si quantum dots, curved surface effect, surface bonds, localized levels

中图分类号:  (Lasers)

  • 42.55.-f
68.65.Hb (Quantum dots (patterned in quantum wells)) 78.45.+h (Stimulated emission) 78.55.Mb (Porous materials)