پديد آورنده :
سليمي پروانه، ليلا
عنوان :
بررسي ابتدا به ساكن خواص ساختاري و الكتريكي بلور و نانوسيم اينديم آرسنايد ﴿InAs)
مقطع تحصيلي :
كارشناسي ارشد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان،دانشكده فيزيك
صفحه شمار :
[هشت]،85ص.:مصور،جدول،نمودار
يادداشت :
ص.ع.به فارسي و انگليسي
استاد راهنما :
هادي اكبرزاده
استاد مشاور :
جواد هاشمي فر
توصيفگر ها :
نانوسيم هاي نيمه رسانا , نظريه تابعي چگالي , شبه پتانسيل , سطوح غير قطبيده , انرژي همدوسي , پيوندهاي آويزان , محصورشدگي كوانتومي
تاريخ نمايه سازي :
89/1/23
تاريخ ورود اطلاعات :
1396/09/28
چكيده فارسي :
به فارسي و انگليسي:قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
Ab initio study of structural and electronic properties of bulk InAs and its nanowires Leila Salimi Parvaneh E mail address l salimi@ph iut ac ir Date of Submission 28 02 2010 Department of Physics Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Dr Hadi AkbarzadehAbstract We have studied the structural and electronic properties of InAs bulk and nanowires by usingdensity functional theory pseudo potential computations with local density approximation Thestable structure of bulk InAs is Zinc Blende ZB although under special experimental conditionsWurtzite WZ InAs has also been observed Due to the high symmetry and low ratio of danglingbonds we have considered triangular and hexagonal WZ nanowires in 0001 direction and hexagonalZB nanowires in 111 direction In order to select facets of the nanowires we calculated formationenergy of nonpolar surfaces of both structures and found that ZB 110 and WZ 1010 are more sta ble than others All nanowires were calculated in the optimized and relaxed supercells Calculatingthe cohesive energy of nanowires with small diameter nanowires were tted by a phenomenologicalmodel to obtain dangling bond energies and then extrapolate the cohesive energy of large diam eter nanowires The extrapolated results indicate that for diameters up to 50 Angstrom the WZnanowires are more stable than ZB nanowires while for larger diameters the contribution of danglingbonds reduces and the results converge to that of bulk InAs In spite of the presence of danglingbonds at surfaces WZ InAs nanowires are semiconducting By the quantum con nement the bandgap increases as the diameter of nanowires reduces but the icrease seems to be slower than what weexpect from simple quantum mechanical model In WZ nanowires the top of valence band is mainlycontributed by As 4p valence electrons while the bottom of conduction band is contributed by In 5pvalence electrons Key Words Semiconductor Nanowires InAs Density Functional Theory Pseudo Potential Nonpolar Surfaces Cohesive Energy Dangling Bonds Quantum Con nement
استاد راهنما :
هادي اكبرزاده
استاد مشاور :
جواد هاشمي فر
