پديد آورنده :
كريمي، حسين
عنوان :
محاسبه ي ابتدا به ساكن اثر نقص هاي نقطه اي غيرذاتي بر خواص ساختاري و الكتروني سولفيدِ استرانسيوم
مقطع تحصيلي :
كارشناسي ارشد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده فيزيك
صفحه شمار :
ب، 87ص.: مصور، جدول، نمودار
يادداشت :
ص. ع. به فارسي و انگليسي
استاد راهنما :
جواد هاشمي فر
استاد مشاور :
مجتبي اعلائي
توصيفگر ها :
درخشندگي , حفره مغزه , محاسبات نظريه تابعي چگالي , نقص هاي نقطه اي , تابعي تركيبي دقيق
استاد داور :
حسين صادقي، اسماعيل عبدالحسيني سارسري
تاريخ ورود اطلاعات :
1395/12/18
چكيده انگليسي :
AbstractDeep understanding of different luminescence phenomena in materials in additions tomodern experimental analysis requires accurate and reliable theoretical studies In thisthesis SrS crystal doped with Ce impurity is our target material for theoretical descriptionof the luminescence phenomena In this regard density functional computations by usingfull potential LAPW technique are employed as powerful and reliable computational tools In addition experimental measurements by external collaborators are used for comparison At the first step possible configurations of the doped crystal are addressed in theframework of first principles thermodynamics and substitution of Sr atom by Ce impurityis argued to be the most stable configuration of the doped SrS compatible withexperimental observations After calculating electronic structure of a group ofsemiconducting compound within different exchange correlation functionals andcomparing the resulting band gaps with experiment we introduce the ex TB mBJ methodfor more reliable calculation of electronic structure of correlated systems containing delectrons Then electronic properties of the stable configuration of Ce doped SrS isinvestigated and the metallic behavior of this system is shown It is argued that neither theHubbard correction scheme nor changing the spin configuration of the system is able toresolve this elaborate problem Moreover following some experimental signals effect ofcore level ionization of the impurity in the electronic properties of the system isinvestigated and performance of this method in correct description of the luminescenceproperties of the doped crystal is discussed Finally effect of Sr vacancy in the Ce dopedSrS is investigated and it is observed that this system provide very good description for theobserved luminescence properties of Ce doped SrS Keywords luminescence core hole Density Functional Theory calculations pointdefects exact hybrid functiona
استاد راهنما :
جواد هاشمي فر
استاد مشاور :
مجتبي اعلائي
استاد داور :
حسين صادقي، اسماعيل عبدالحسيني سارسري
