Dai Liping, Bremner Stephen P, Tan Shenwei, Wang Shuya, Zhang Guojun, Liu Zongwen
State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, No 4, Section 2, Jianshe North Road, Chengdu, 610054 China ; Australian Centre for Microscopy and Microanalysis, The University of Sydney, Chemical Engineering Building, Sydney, 2006 Australia.
School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney, 2052 Australia.
Nanoscale Res Lett. 2015 Apr 29;10:202. doi: 10.1186/s11671-015-0908-1. eCollection 2015.
The effect of Sb spray time on the structure of InAs/GaAs quantum dot (QD) systems with Sb spray prior to the capping of a GaAs layer was determined by a Raman scattering study. The Raman spectra of the InAs/GaAs system show two phonon signal bands related to interface (IF) defects, located at the low-energy side of InAs QDs and GaAs cap layer main phonon peaks, respectively. The intensity ratio of the IF defect relative phonon signal to its corresponding main peak shows a significant decrease with the Sb spray time increasing from 0 to 15 s, but increases for spray times larger than 15 s. In addition, the InAs QD phonon peaks appear to be resolved with improved symmetry for 15 s of spray time. Finally, the GaAs transverse optical (TO) phonon peak is seen to vary with Sb spray time, both in terms of the intensity and the peak position, in a similar manner to the other results. Taken together, these results suggest the InAs/GaAs QDs with a 15-s Sb spray lead to a GaAs capping layer with less strain at the IF with the QDs and a lower density of crystalline defects.
81.05.Ea; 81.07.-b; 81.07.Ta.
通过拉曼散射研究确定了在砷化镓层覆盖之前进行锑喷涂时，锑喷涂时间对砷化铟/砷化镓量子点（QD）系统结构的影响。砷化铟/砷化镓系统的拉曼光谱显示出与界面（IF）缺陷相关的两个声子信号带，分别位于砷化铟量子点和砷化镓覆盖层主要声子峰的低能量侧。IF缺陷相对声子信号与其相应主峰的强度比随着锑喷涂时间从0秒增加到15秒而显著降低，但在喷涂时间大于15秒时增加。此外，对于15秒的喷涂时间，砷化铟量子点声子峰似乎以改善的对称性得到分辨。最后，观察到砷化镓横向光学（TO）声子峰在强度和峰位置方面都随锑喷涂时间而变化，与其他结果类似。综合来看，这些结果表明，进行15秒锑喷涂的砷化铟/砷化镓量子点会导致在与量子点的界面处具有较小应变且晶体缺陷密度较低的砷化镓覆盖层。
81.05.Ea；81.07.-b；81.07.Ta。
