分子束外延生长亚稳态ZnCdSe/MgSe低维量子阱结构及其光学性质  

Optical Properties of Zn_xCd_(1-x)Se/MgSe Quantum Wells Grown on InP Substrate by Molecular Beam Epitaxy

作　　者：李炳生[1] SHEN Ai-dong 

机构地区：[1]哈尔滨工业大学基础与交叉科学研究院,黑龙江哈尔滨150080 [2]Department of Electrical Engineering,The City College of the City University of New York

出　　处：《发光学报》2013年第7期811-815,共5页Chinese Journal of Luminescence

摘　　要：采用分子束外延技术在(001)取向的InP衬底上外延生长了亚稳态的ZnxCd1-xSe/MgSe低维量子阱结构,并通过光致发光和子带吸收方法,分析其能带结构。在单量子阱样品制备过程中,高能电子衍射强度振荡表明MgSe可以实现二维生长模式,衍射图样证明其为亚稳态闪锌矿结构。通过引入厚的ZnxCd1-xSe空间层,抑制了MgSe垒层的相变,并能进一步提高样品的结晶质量,得到高结晶质量的多量子阱结构。通过计算不同阱宽的能带与光致发光实验比较,证明了ZnxCd1-xSe/MgSe的导带带阶为1.2 eV,价带带阶为0.27 eV。为了进一步验证其能带结构,制备了电子掺杂的ZnxCd1-xSe/MgSe的多量子阱,观测到半高宽很窄的中红外吸收。利用发光谱确定的带阶计算了量子阱中子带的吸收波长,和实验结果非常吻合。设计了一种双量子阱结构,计算结果显示,通过利用量子阱中的耦合效应,可以实现1.55μm光通信波段的吸收。We studied the band gap structure of ZnxCd1-xSe/MgSe heterostructure grown on(001) InP substrates by molecular beam epitaxy.In the single quantum well growth of ZnxCd1-xSe/MgSe,the in situ reflection high energy electron diffraction intensity oscillations and streak patterns demonstrate that zincblende(ZB) MgSe has been formed.Furthermore,with the introduction of thick ZnxCd1-xSe spacer layers,the ZB MgSe/ZnxCd1-xSe multi-quantum wells can be obtained.Based on the results of photoluminescence and calculation,the offset for conduction and valence band in MgSe/ZnxCd1-xSe heterostructure is estimated to be 1.2 eV and 0.27 eV,respectively.Using the estimated value of band offset,the calculated ISB transition energies agree well with results of infrared absorption experiments.With such a large band offset,ISB transitions in this material system could be extended to 1.55 μm within an asymmetric double quantum wells with coupling effects.

关 键 词：分子束外延 Ⅱ-Ⅵ族量子阱 闪锌矿MgSe 能带带阶 

分 类 号：O482.31[理学—固体物理]