Temperature dependence of photoluminescence from self-organized Ge quantum dots with large size and

• 出 处: Science China(Physics,Mechanics & Astronomy)
• 发表日期: 2011年02期
• 关键词: organized compressive negligible overcome raising phonon trapped fitted surfacta

Photoluminescence(PL) from self-organized Ge quantum dots(QDs) with large size and low density has been investigated over a temperature range from 10 to 300 K using continuous-wave(CW) optical excitation.The integrated PL intensity of QDs observed is negligible at about 10 K and rapidly increases with raising temperature up to 100 K.Through analyzing the PL experimental data of the QDs and wetting layer(WL),we provide direct evidence that there exists a potential barrier,arising from the greater compressive strain surrounding large QDs,which could trap carriers in WL at low temperatures and could be overcome via increasing temperature.

Photoluminescence (PL) from self-organized Ge quantum dots (QDs) with large size and low density has been investigated over a temperature range from 10 to 300 K using continuous-wave (CW) optical excitation. The integrated PL intensity of QDs observed is negligible at about 10 K and rapidly increases with raising temperature up to 100 K. Through analysis the PL experimental data of the QDs and wetting layer (WL), we provide direct evidence that there exists a potential barrier, arising from the greater compressive strain surrounding large QDs, which could trap carriers in WL at low temperatures and could be overcome via increasing temperature.