Development, Characterization and Stress Analysis of Fluorine-doped Tin Oxide Thin Films as a Corrosion Barrier for Electrolysis

Development, Characterization and Stress Analysis of Fluorine-doped Tin Oxide Thin Films as a Corrosion Barrier for Electrolysis
Author: Kelly J.. Lambright
Publisher:
Total Pages: 0
Release: 2021
Genre: Electrolysis
ISBN:

As society continues to use fossil fuels as its main source of energy, both global climate change and fuel source depletion are pressing concerns. Sunlight is the most ubiquitous energy source available, but is unreliable as an on-demand source of energy. However, using solar energy to produce hydrogen gas via electrolysis for use in fuel cells is a promising clean energy alternative for electricity production. The most direct method of solar powered water electrolysis is a photoelectrochemical (PEC) device, where a photovoltaic is submersed in an aqueous electrolyte to produce hydrogen and oxygen upon irradiation of the photoanode. This photoanode is very susceptible to failure due to the corrosive conditions used for water electrolysis, and therefore needs a transparent, yet conductive anti-corrosive protection layer. Fluorine doped tin oxide is a transparent conductive oxide, and is a potential protective layer for a PEC device due to its good stability under harsh environmental conditions. One of the most commonly used inexpensive deposition methods for tin oxide thin films is spray pyrolysis with tin chloride precursors at elevated temperatures of 350 to 550 °C. As these temperatures are too high for deposition onto the photovoltaic device used in this research, other precursors as well as solution additives that can lower the decomposition temperature were explored in this work. Films were successfully deposited at 250 to 280 °C using dibutyltin diacetate and the solution additive erbium chloride. The corrosion stability of these films was compared to films produced with the commercially used tin tetrachloride precursor. It was found that films prepared with dibutyltin diacetate showed much stronger resistance to corrosion than those obtained from tin tetrachloride. The films were analyzed with scanning electron microscopy, energy dispersive X-ray spectroscopy and powder X-ray diffraction. Film topographies were strongly affected by the precursor, and chloride incorporation was observed for the films produced with tin tetrachloride. Such ion incorporation can change the stress state of a thin film and may affect its corrosion resistance. Strain measurements using powder X-ray diffraction were carried out in order to analyze the deposited films' levels of stress. The results showed that the films deposited from tin tetrachloride were more stressed, which is the likely cause of the higher corrosion susceptibility of these films. Additionally, the solution additive erbium chloride and its interaction with the precursor dibutyltin diacetate was investigated using infrared spectroscopy and single crystal X-ray diffraction. It was found that erbium chloride reacts with dibutyltin diacetate to form compounds that contain small pre-formed tin oxide moieties. One of these compounds, C36H78Sn4O8, was successfully prepared by direct synthesis from appropriate precursors. This material decomposed at significantly lower temperatures, and could be used for direct deposition of tin oxide films at 230 to 240 °C. Finally, a preliminary study into cation doping of tin oxide films was carried out to evaluate their response to the oxygen evolution reaction. The resultant films were tested with linear sweep voltammetry and it was found that the incorporation of cobalt (III) into the tin oxide films potentially lowers the onset of oxidation for the oxygen evolution reaction.

Commencement

Commencement
Author: University of Minnesota
Publisher:
Total Pages: 164
Release: 1988
Genre: Commencement ceremonies
ISBN:

Thin Film Solar Cells

Thin Film Solar Cells
Author: Jef Poortmans
Publisher: John Wiley & Sons
Total Pages: 504
Release: 2006-10-16
Genre: Science
ISBN: 0470091266

Thin-film solar cells are either emerging or about to emerge from the research laboratory to become commercially available devices finding practical various applications. Currently no textbook outlining the basic theoretical background, methods of fabrication and applications currently exist. Thus, this book aims to present for the first time an in-depth overview of this topic covering a broad range of thin-film solar cell technologies including both organic and inorganic materials, presented in a systematic fashion, by the scientific leaders in the respective domains. It covers a broad range of related topics, from physical principles to design, fabrication, characterization, and applications of novel photovoltaic devices.