The equilibrium composition in Ge_xSi_1-_x/Si self-assembled alloy quantum dot  

作　　者：王东林 俞重远 刘玉敏 叶寒 芦鹏飞 赵龙 郭晓涛 

机构地区：[1]Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications),Ministry of Education

出　　处：《Chinese Physics B》2010年第8期500-505,共6页中国物理B（英文版）

基　　金：Project supported by the National High Technology Research and Development Program of China(Grant No.2009AA03Z405);the National Natural Science Foundation of China(Grant Nos.60908028,60971068,10979065,and 10947150);the High School Innovation and Introducing Talent Project of China(Grant No.B07005)

摘　　要：The equilibrium composition in strained quantum dot is the result of both elastic relaxation and chemical mixing effects, which have a direct relationship to the optical and electronic properties of the quantum-dot-based device. Using the method of moving asymptotes and finite element tools, an efficient technique has been developed to compute the composition profile by minimising the Gibbs free energy in self-assembled alloy quantum dot. In this paper, the composition of dome-shaped CexSi1-x/Si quantum dot is optimized, and the contribution of the different energy to equilibrium composition is discussed. The effect of composition on the critical size for shape transition of pyramid-shaped GeSi quantum dot is also studied.The equilibrium composition in strained quantum dot is the result of both elastic relaxation and chemical mixing effects, which have a direct relationship to the optical and electronic properties of the quantum-dot-based device. Using the method of moving asymptotes and finite element tools, an efficient technique has been developed to compute the composition profile by minimising the Gibbs free energy in self-assembled alloy quantum dot. In this paper, the composition of dome-shaped CexSi1-x/Si quantum dot is optimized, and the contribution of the different energy to equilibrium composition is discussed. The effect of composition on the critical size for shape transition of pyramid-shaped GeSi quantum dot is also studied.

关 键 词：equilibrium composition quantum dot method of moving asymptotes 

分 类 号：O471.1[理学—半导体物理]