Date of Graduation

Fall 2021

Degree

Master of Science in Materials Science

Department

Physics, Astronomy, and Materials Science

Committee Chair

Kartik Ghosh

Abstract

Oxide heterostructures have drawn great attention lately, due to their environment-friendly properties and potential applications in optoelectronic devices. In this work, a simulation study of a heterojunction solar cell was performed with SCAPS (a solar cell simulator) using TiO2 as an n-type and CuO as a p-type layer. The thickness and the dopant-dependent simulations have shown that the solar cell operates at a maximum efficiency of 19.2% when the thickness of the TiO2/CuO layers is chosen 1.4µm/1.2µm compared to the 11.5% efficiency when FTO is replaced with ITO. An indium-doped tin oxide (ITO) vs fluorine-doped tin oxide (FTO) comparison study was carried out where FTO worked better than ITO as a transparent anode electrode in this structure. Gold worked better as a cathode electrode from a range of metallic elements, and it was observed that efficiency increases with the increase in the metalwork function. Based on the simulation results, the oxide-based heterojunction was fabricated on ITO substrates using pulsed laser deposition (PLD), spin coating, and sputtering techniques. Structural-property correlations were conducted using x-ray diffraction, Raman spectroscopy, scanning electron microscopy, and electrical measurements i.e., diode characteristics test with light and without light. The rutile phase of TiO2 was successfully grown on glass, quartz, and ITO to find the best growth parameters for TiO2 film. Same experimental works were carried out for the CuO layer growth where spin coating, PLD, and a combination of both techniques were used and compared. Finally, the cathode layer of gold was deposited by the sputtering technique. The solar cell characterization was performed by the I-V measurement using a standard solar simulator and UV-VIS spectroscopy. Origin, Vesta, and Mercury software were used for data analysis. It was observed that the devices where the CuO layer was PLD grown have more absorbance of the visible light spectrum. Also, the PLD grown samples worked better, showed an efficiency region in the I-V curve, and performed solar characteristics under the visible light spectrum.

Keywords

thin films, heterostructure, solar cell, titanium dioxide, copper oxide, indium doped tin oxide, pulsed layer deposition, X ray diffraction, Raman spectroscopy, electrical characterization

Subject Categories

Other Materials Science and Engineering | Power and Energy | Semiconductor and Optical Materials

Copyright

© Sajal Islam

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