Document Details

Document Type : Thesis 
Document Title :
MICROSTRUCTURE AND THERMAL PROPERTIES OF CDZNTE QUANTUM DOTS
التركيب الدقيق والخواص الحرارية للنقاط الكمية من المركب الثلاثي المكون من الكادميوم والزنك والتيلريوم
 
Subject : Faculty of Sciences 
Document Language : Arabic 
Abstract : Colloidal semiconductor nanocrystals is under high scientific attention owing to their unappalled size-dependent properties. Consequently, many scientific works have been done on studying the characterization of nanostructures fabricated by colloidal method especially for II-VI semiconductors. Up to now, no systematic studies of thermal properties have been done on the ternary mixed cadmium zinc telluride (Cd1-xZnxTe) quantum dots (QDs). In this thesis synthesize Cd1-xZnxTe capped with mercaptoacetic acid (MAA) QDs in water mixed solution with various compositions of Zn with employing new precursors .The structure and morphology of these QDs were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The optical properties were investigated by using UV–Visible absorption and thermal properties by thermogravimetric analysis (TGA).The results confirm formation of Cd1-xZnxTe QDs alloy with a hexagonal and cubic phase and showed the presence of capping elements at the surface of QDs. The optical band gap of Cd1-xZnxTe QDs has been observed to increase as the composition of Zn in host matrix increases. The particle sizes attained from optical absorption measurements have very low value in comparison to the diameter of exciton Bohr indicating that the MAA-capped Cd1-xZnxTe QDs are in a strong confinement regime. TGA results exhibited that the melting point (Tm) of Cd1-xZnxTe QDs is larger than Tm of CdTe QDs; this indicates that Cd1-xZnxTe QDs has high stability. Due to the large value of surface per volume ratio of the nanoparticles, Tm of Cd1-xZnxTe QDs is lower than the Tm of bulk Cd1-xZnxTe.These results render good properties for Cd1-xZnxTe QDs, which makes it promising for future applications such as thermal detectors. 
Supervisor : Prof. Wageh Mohammed Helmy Swelm 
Thesis Type : Master Thesis 
Publishing Year : 1439 AH
2018 AD 
Added Date : Monday, May 14, 2018 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
إبتسام حسن الزهرانيAl Zahrani, Ebtisam HassanResearcherMaster 

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