کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5423720 | 1507949 | 2010 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Structural and electronic properties of group III Rich In0.53Ga0.47As(001)
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کلمات کلیدی
Surface relaxation and reconstruction - آرامسازی و بازسازی سطحSemiconducting surfaces - سطوح نیمه هادیBader charge - شارژ بدرScanning tunneling spectroscopies - طیف سنجی تونل زنی اسکنDensity functional calculations - محاسبات عملکردی تراکمScanning tunneling microscopy - میکروسکوپ تونلی روبشی Indium gallium arsenide - هندسی گالیم آرسنید
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
The structural and electronic properties of group III rich In0.53Ga0.47As(001) have been studied using scanning tunneling microscopy/spectroscopy (STM/STS). At room temperature (300Â K), STM images show that the In0.53Ga0.47As(001)-(4Â ÃÂ 2) reconstruction is comprised of undimerized In/Ga atoms in the top layer. Quantitative comparison of the In0.53Ga0.47As(001)-(4Â ÃÂ 2) and InAs(001)-(4Â ÃÂ 2) shows the reconstructions are almost identical, but In0.53Ga0.47As(001)-(4Â ÃÂ 2) has at least a 4Ã higher surface defect density even on the best samples. At low temperature (77Â K), STM images show that the most probable In0.53Ga0.47As(001) reconstruction is comprised of one In/Ga dimer and two undimerized In/Ga atoms in the top layer in a double (4Â ÃÂ 2) unit cell. Density functional theory (DFT) simulations at elevated temperature are consistent with the experimentally observed 300Â K structure being a thermal superposition of three structures. DFT molecular dynamics (MD) show the row dimer formation and breaking is facilitated by the very large motions of tricoodinated row edge As atoms and z motion of In/Ga row atoms induced changes in As-In/Ga-As bond angles at elevated temperature. STS results show there is a surface dipole or the pinning states near the valence band (VB) for 300Â K In0.53Ga0.47As(001)-(4Â ÃÂ 2) surface consistent with DFT calculations. DFT calculations of the band-decomposed charge density indicate that the strained unbuckled trough dimers being responsible for the surface pinning.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Surface Science - Volume 604, Issues 19â20, September 2010, Pages 1757-1766
Journal: Surface Science - Volume 604, Issues 19â20, September 2010, Pages 1757-1766
نویسندگان
Jian Shen, Jonathon B. Clemens, Evgueni A. Chagarov, Darby L. Feldwinn, Wilhelm Melitz, Tao Song, Sarah R. Bishop, Andrew C. Kummel, Ravi Droopad,