Open AccessThe structure of silicon quantum dots and key factors for emission in different environment
Author(s) -
Weiqi Huang,
Quan Lyu,
Xiaoyun Wang,
Zhang Rong-Tao,
Yu Shi-Qiang
Publication year - 2011
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.60.017805
Subject(s) - photoluminescence , dangling bond , materials science , quantum dot , silicon , metastability , band gap , electron , nanosecond , surface states , optoelectronics , laser , physics , optics , surface (topology) , geometry , mathematics , quantum mechanics
Silicon quantum dots fabricated by nanosecond pulse laser in nitrogen, oxygen or air environment have enhancement in photoluminescence emission. The stimulated emission was observed at about 700 nm. It is difficult to recognize the difference between the photoluminescence peaks from samples in different environments, which is because of the same structure of the electron states in the band gap for different samples. The calculation results show that the same structure of the localized states forms in the band gap when silicon dangling bonds on surface of quantum dots are passivated by nitrogen or oxygen. It is the localized states that could catch the electrons from the conduction band to form metastable states, which is the key factor to enhance photoluminescence emission.