摘要
利用金属有机化合物气相沉积（MOCVD）技术生长了双层InAs/GaAs量子点,并将GaInP作为应力补偿层引入到其中,采用原子力显微镜（AFM）对量子点的结构和生长质量进行了表征与分析.实验结果表明,应变补偿层的采用可有效改善第二层量子点质量：（1）面密度最高可达7.5×1010 cm-2,而没有应变补偿层的样品的面密度仅为5.8×1010 cm-2;（2）缺陷岛密度可从不采用应变补偿时的9.6×107 cm-2降低至2.8×107 cm-2;（3）量子点的均匀性和尺寸也明显改善.此外,不同应变补偿层厚度比较实验结果显示,厚度过高或过低的应变补偿层都不能起到很好的补偿作用,取1～3 nm之间为佳;不同GaInP补偿层组分的比较实验结果表明,Ga组分为0.566的样品补偿效果比0.606的样品更好.
Two-stack InAs/GaAs quantum dot structures with GaInP strain compensation layers inserted were grown by metal organic chemical vapor deposition.The structure and quality of the quantum dots were investigated using atomic force microscopy.The results show that the quantum dots＇ quality of the second layer were improved by using strain compensation layer：（1）the surface dot density up to 7.5 × 1010 cm-2,which is significantly larger than the sample without strain compensation layer,5.8 × 1010 cm-2 ; （2） the defect island density reduce from 9.6 × 107 cm-2 to 2.8× 107 cm-2 ; （3）the uniformity and size of the quantum dots are also significantly improved.The influence of the thickness and the Ga concentration of the GaInP strain compensation layers is also discussed,it reveals that it can not play a very good role in compensating if the thickness is too thick or too thin,the optimum value is between 1 nm to 3 nm.And the sample with a Ga concentration of 0.566 is better than the sample of 0.606.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2014年第6期29-32,共4页
Materials Reports
基金
云南省重点基金(2009CC012)
云南省中青年学术技术带头人后备人才(2008PY054)
长江学者和创新团队发展计划
