University of Wollongong Research Online University of Wollongong Thesis Collection 2017+ University of Wollongong Thesis Collections 2020 Thermoelectric Performance Study of Cost-Effective Lead Chalcogenides Andrew Manettas Follow this and additional works at: https://ro.uow.edu.au/theses1 University of Wollongong Copyright Warning You may print or download ONE copy of this document for the purpose of your own research or study. The University does not authorise you to copy, communicate or otherwise make available electronically to any other person any copyright material contained on this site. You are reminded of the following: This work is copyright. Apart from any use permitted under the Copyright Act 1968, no part of this work may be reproduced by any process, nor may any other exclusive right be exercised, without the permission of the author. Copyright owners are entitled to take legal action against persons who infringe their copyright. 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For further information contact the UOW Library: [email protected] Thermoelectric Performance Study of Cost-Effective Lead Chalcogenides This thesis is presented to fulfil the requirements for the award of the Degree of Doctor of Philosophy Institute for Superconducting and Electronic Materials Faculty of Engineering and Information Sciences University of Wollongong 2020 Andrew Manettas Supervisor – Alexey V Pan DECLARATION This thesis does not contain any material that has been submitted for the award of any degree from this or any other university and, to the best of my knowledge, contains solely original work, not published or written by any other person, except where referenced or acknowledged. Andrew Manettas May 2020 ACKNOWLEDGEMENTS I would like to begin my acknowledgements with the start of my research studies. My first experience in research was my honours year at UOW, of which Alexey Pan was the honours coordinator. I did not know what I wanted to do after I graduated, but I really enjoyed my honours year and I knew I would have liked to continue doing scientific research. I spoke to Alexey after I finished my honours thesis and he was the one that put me in touch with Sima Aminorroaya-Yamini. So firstly, I need to thank Alexey for helping me begin, and continue my work as a researcher. Sima was an excellent supervisor; I was starting in a completely new field and I had many questions to ask her. She always left her office door open and encouraged her group members to come and ask questions. I often went in for a quick question and she was always happy to help. Every time I stepped into her office I learned something new, it was always an invaluable experience and I thank her for being so generous with her time. Working under Sima was the core group of post-grad students, myself, Rafael Santos, Vaughan Patterson, Jacob Byrnes and Xavi Reales. We had a group chat where we would ask each other questions, and it was mostly a wonderful tool to help each other get through our studies, as well as have some fun discussions. Then there were the other students who would come for lunch, we would often joke that lunch was the best part of the day! Jonathan Kent, Florian Gebert, Antony Jones, and all the others who I have not mentioned, you guys helped make each day a little bit more exciting. It was a great time to chat with other people about life, our favourite TV shows, and most importantly talk about our scientific work. There were many occasions where, after lunch, we would head back into the lab together to help one another with a problem. We also had many summer students under Sima’s group come and go throughout my time there and it was always exciting to teach them about our work, show them something new, as well as share and enjoy life experiences and for the international students, hopefully help them enjoy their time in Australia. I slowly learned that doing a PhD was impossible to do on my own, and that I needed the help of others to ensure I had the correct equipment, and maintain said equipment. The staff of the AIIM workshop, in particular Rob Morgan and Paul Hammersley, were instrumental in my experimental work. I always felt welcome in the workshop, and you guys were always happy to help me in any way you could. After Sima left, I had Yusuke Yamauchi as my PhD supervisor. He assisted in writing my papers and set me up with an internship in Japan. This was an invaluable experience for me, I had never been overseas before this, and was never the kind of person to want to go traveling, let alone live in a new country! I was able to work in the labs in Japan and learn a lot of new scientific skills, as well as learn a lot about myself. I could write many pages on my time in Japan, but I will leave that for another time. Thank you for the wonderful experience Yusuke, I would never have had the chance to do that without you and I thank you for it. On my return from Japan, I had changed supervisors yet again, coming full circle to the start of my research career and now having Alexey Pan as my PhD supervisor. Alexey was enthusiastic about taking over my project and was able to get me a scholarship extension. This was a huge deal for me, I needed to be able to support myself and Alexey understood that. He let me focus solely on my PhD, finish my work and I was fortunate enough that he was able to assist me. Having Alexey as a supervisor has been a fantastic experience, thank you for helping me finish off my thesis and I hope our paths cross again soon. Going in to ISEM every day and learning something new was a wonderful experience, and in particular I have to thank one person again. Rafael Santos sat behind me, and was always happy to be annoyed by my silly questions and show me how to be a better scientist. All I had to do was spin my chair around and ask for help, and he would be happy to take the time to assist. I was just beginning my scientific career; I didn’t have much to offer in return so I would always try and repay the favour by helping him wherever possible. If he needed an extra set of hands fixing some equipment, I would try and help, and then you would spend half an hour telling me how to correctly turn something off, showing me how everything worked and explaining the fundamental physics behind it and I loved it. I now have such a deep understanding of the instruments I used, how they work and what they do, and I have you to thank for it. I continue to have this thirst for knowledge, I want to have a greater understanding of the work I am doing and why, and this follows through to everyday life. I am now more inquisitive, more confident, and overall a better person because of what you taught me. Thank you for teaching me everything from how to use Microsoft Powerpoint to the calibration of a thermoelectric measurement device. As always, I need to thank my family and friends for being so supportive of my student lifestyle. I am the first in my immediate family to do a post-graduate degree, and without the help of Mum and Dad encouraging me to do continue my studies I could not have done it. I am very lucky that I was able to spend so long at uni, and even luckier that it all worked out so well. I’ll get you back one day, I promise. In my time at UOW I have made lifelong friends that are all still confused by what a PhD is and what I do at work, but you guys help distract me from the academic life, give me the break that I need to get me refreshed for my PhD again on Monday. Thank you for all the social gatherings and movie nights that were an excellent source of stress relief. My thesis is a combination of all the people that have helped me along the way, thank you again to all those mentioned, and even to those I haven’t (sorry if I didn’t mention you), your help no matter how small has made an impact on my life and I am thankful for it. ABSTRACT Global warming and resource management is steadily becoming a more pressing world issue. The use of renewable energy is a solution to many of the world’s problems and if a useful renewable energy source is found, its application would potentially be immediate and widespread across the world. One of the biggest energy sources that could be harnessed is waste heat, which makes up around 70 per cent of the total energy produced by major industry in developed countries like the USA.