Study the electronic properties of CdTe nanostructure

العناوين الأخرى

دراسة الخصائص الإلكترونية لتركيب CdTe النانوني

مقدم أطروحة جامعية

al-Hasan, Hamid Ahmad Fayyd

مشرف أطروحة جامعية

Husayn, Muhammad Taqi

أعضاء اللجنة

al-Ias, Maysun F. A.
Amin, Hamid M.
Rashid, Bassam Ghalib

الجامعة

جامعة بغداد

الكلية

كلية العلوم

القسم الأكاديمي

قسم الفيزياء

دولة الجامعة

العراق

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2013

الملخص الإنجليزي

Gaussain 03 code of Ab-initio Density functional theory (DFT) coupled with large unit cell method is used to determine the electronic structure properties of II-VI zinc blende cadmium tellurium (CdTe) at nanocrystals size (8,16,54 and 64) of core atoms for 3D periodic boundary condition (PBC) and 2D (PBC) calculation were used to simulated oxygenated (001)-(1x1) surface.

The crystal length was between 1.93- 2.54 nm.

In present work it has investigated properties include the total energy , cohesive energy , energy gap , valence and conduction bands width , ionicity and degeneracy of states for core and surface parts.

The results obtained show that the total energy and cohesive energy of CdTe nanocrystals decreases with increasing the size of core atoms and this cause a decrease of lattice constant respectively, and the lattice constant for the surface part is smaller than of core part.

The ionicity of the core part decreases with increasing number of core atoms.

The energy gap of core part at the size of 8 core atoms is about 3.33 eV compare with the energy gap for surface part with the same size which is equal 0.136 eV.

The valence and conduction bands width increase with increasing number of core atoms , while conduction band width is wider on the surface.

The results also show that the density of states increases with increasing the number of core atoms, and the density of states of core part is higher than that at surface part, this is due to the broken symmetry at the surface discontinuity and existence of new kind of atoms (oxygen atoms).

Generally, the results obtained from ab-initio method in the present work are in good agreement with others theoretical and experimental studies.

التخصصات الرئيسية

الفيزياء

الموضوعات

• الخواص الكهربائية
• الأجسام الصلبة
• أشباه الموصلات

عدد الصفحات

78

قائمة المحتويات

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-606959