应变层超晶格Zn_(1-x)Cd_xSe/ZnSe和ZnSe/ZnS_xSe_(1-x)光致发光谱

Photoluminescence Spectra of Zn 1- x Cd x Se/ZnSe and ZnSe/ZnS x Se 1- x Strained Layer Supperlattices

本文报道了分子束外延生长的应变层超晶格Ｚｎ０．７７Ｃｄ０．２３Ｓｅ／ＺｎＳｅ和ＺｎＳｅ／ＺｎＳ０．１２Ｓｅ０．８８的光致发光谱．分析了影响激子线型展宽的主要因素．定量表征了４．４Ｋ下合金涨落和阱厚涨落对线型展宽的贡献．理论分析表明，在低温（４．４Ｋ）下，合金涨落和阱宽涨落对线型展宽起主导作用．对比结果显示，Ｚｎ０．７７Ｃｄ０．２３Ｓｅ／ＺｎＳｅ超晶格的合金涨落和阱宽涨落对线型展宽的贡献大于ＺｎＳｅ／ＺｎＳ０．１２Ｓｅ０．

Abstract This paper presents photoluminescence sprectra of Zn 0.77 Cd 0.23 Se/ZnSe and ZnSe/ZnS 0.12 Se 0.88 Strained Layer Supperlattices(SLS). The dominant broadening mechanisms of linewidths (FWHM) for free exciton emissions are analysised. The contribution of alloy concentration fluctuation and well thickness fluctuation to linewidth are calculated. The theoretical results show that the predominant mechanisms of broadening at low temperature (4 4K) are alloy concentration and well thickness fluctuation. Furthermore, it has demonstrated that the quality of ZnSe/ZnS x Se 1- x is superior to that of Zn 0.77 Cd 0.23 Se/ZnSe.