摘要
研究了用分子束外延(MBE)在GaAs衬底上生长GaSb薄膜的工艺。为了减小因晶格失配度较大所引起的位错密度,采用低温GaSb作为缓冲层,有效降低了外延层中的位错密度,提高了晶体质量。通过X射线双晶衍射仪和原子力显微镜测试分析,得到低温GaSb缓冲层的优化生长参数:厚度为20nm,生长速率为1.43μm/h,V/III束流比为2.0。并在此基础上研究了GaSb薄膜的发光特性:GaSb薄膜的光致发光光谱主要由束缚激子(BE4)和施主-受主对(D-A)辐射复合发光峰组成,在50K时其发光峰强度最强,半峰宽最窄。
The hetero epitaxial growth of GaSb on GaAs substrates by molecular beam epitaxy （MBE） was investigated. In order to decrease the dislocation density caused by the lattice mismatch, GaSb of low temperature （LT） was used as a buffer layer. It was found that the dislocation density of GaSb epilayer is decreased and the crystal quality is improved effectively. The growth parameters of LT GaSb buffer layer were studied by means of the double crystals X-ray diffraction （DCXRD） and atomic force microscope （AFM）. It was found that the optimum thickness, growth rate, and Ⅴ/Ⅲbeam equivalent pressure ratio were 20 nm, 1.43 μm/h and 2.0, respectively. Finally, the photoluminescence property of GaSb was studied on the basis of the optimized growth conditions of buffer layer. The spectra of GaSb film were composed of the exciton （BE4） and the dominate photoluminescence （PL） transited by donor-acceptor pair （D-A）, with the strongest intensity of BE4 line at 50 K, and the narrowest full width at half maximum （FWHM）.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2007年第2期339-343,共5页
Rare Metal Materials and Engineering
基金
国家自然科学基金(50272019)
国家高技术研究发展计划("863"计划)项目资助(2003AA305860)
关键词
分子束外延
GASB
缓冲层
发光特性
molecular beam epitaxy
GaSh
buffer layer
luminescence property
