Date of Graduation

Summer 2019

Degree

Master of Science in Materials Science

Department

Physics, Astronomy, and Materials Science

Committee Chair

Kartik Ghosh

Keywords

heterostructures, optoelectronics, crystallinity, vibrational states, band gap, photoluminescence, hydrothermal synthesis

Subject Categories

Semiconductor and Optical Materials

Abstract

Heterostructures consisting of at least two layers of dissimilar materials have always been well studied due to potential applications in nano-electronic and optoelectronic devices. In this study, I have investigated the structural and physical properties of zinc oxide -zinc sulfide (ZnO-ZnS) based heterostructures of thin films and core-shell nanoparticles. Pulsed laser deposition technique was employed to grow ZnO thin film on sapphire substrate. ZnO-ZnS heterostructures were obtained using hydrothermal synthesis where thiourea has served as a precursor solution for the source of sulfur. X-ray diffraction analysis on the parent and the sulfidized samples gives the information about the crystallinity and the phase of the heterostructures. Scanning electron microscope analysis provides the morphological and constituent elemental information of the heterostructures. Variation of the time and temperature of the sulfidation can alter the structure and properties of the heterostructures. At a given temperature, the amount of sulfidation depends on the exposure time on the sulfur rich environment. The more the availability of sulfur ions due to thiourea decomposition, the more is the growth of ZnS at the ZnO-ZnS interface. Raman spectroscopy gives the vibrational states present in the both parent and synthesized heterostructures while photoluminescence analysis provides information about optical band gap and defect states that are present in the heterostructures.

Copyright

© Sanchali Das

Open Access

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