Correlated electron-hole transitions in wurtzite GaN quantum dots：the effects of strain and hydrostatic pressure

• Published in: Journal of semiconductors 2012-05, Vol.33 (5), p.6-12
• Main Author: 郑冬梅 王宗篪 肖波齐
• Format: Article
• Language: English
• Subjects: Emission; Gallium nitrides; Hydrostatic pressure; Quantum dots; Semiconductors; Strain; Wavelengths; Wurtzite; 发射波长; 应变效应; 氮化镓; 电子; 空穴; 纤锌矿结构; 量子点; 静水压力
• ISSN: 1674-4926
• DOI: 10.1088/1674-4926/33/5/052002

Within the effective-mass and finite-height potential barrier approximation,a theoretical study of the effects of strain and hydrostatic pressure on the exciton emission wavelength and electron-hole recombination rate in wurtzite cylindrical GaN/Al_xGa_（1-x）N quantum dots（QDs） is performed using a variational approach.Numerical results show that the emission wavelength with strain effect is higher than that without strain effect when the QD height is large（〉 3.8 nm）,but the status is opposite when the QD height is small（〈 3.8 nm）.The height of GaN QDs must be less than 5.5 nm for an efficient electron-hole recombination process due to the strain effect.The emission wavelength decreases linearly and the electron-hole recombination rate increases almost linearly with applied hydrostatic pressure.The hydrostatic pressure has a remarkable influence on the emission wavelength for large QDs,and has a significant influence on the electron-hole recombination rate for small QDs.Furthermore,the present numerical outcomes are in qualitative agreement with previous experimental findings under zero pressure.