Purdue University Purdue e-Pubs Open Access Dissertations Theses and Dissertations January 2015 Solution Routes to Metal Chalcogenide and Zinc Oxide Thin iF lms for Device Applications Ruihong Zhang Purdue University Follow this and additional works at: https://docs.lib.purdue.edu/open_access_dissertations Recommended Citation Zhang, Ruihong, "Solution Routes to Metal Chalcogenide and Zinc Oxide Thin iF lms for Device Applications" (2015). Open Access Dissertations. 1441. https://docs.lib.purdue.edu/open_access_dissertations/1441 This document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact [email protected] for additional information. Graduate School Form 30 Updated 1/15/2015 PURDUE UNIVERSITY GRADUATE SCHOOL Thesis/Dissertation Acceptance This is to certify that the thesis/dissertation prepared By Ϋ·¸±²¹Æ¸¿²¹ Entitled ͱ´«¬·±²Î±«¬»•¬±Ó»¬¿´Ý¸¿´½±¹»²·¼»¿²¼Æ·²½Ñ¨·¼»Ì¸·²Ú·´³•º±®Ü»ª·½»ß°°´·½¿¬·±²• For the degree of ܱ½¬±®±ºÐ¸·´±•±°¸§ Is approved by the final examining committee: Ý¿®±´ßòØ¿²¼©»®µ»® ݱ󽸿·® οµ»•¸ß¹®¿©¿´ ݱ󽸿·® Û´´·±¬¬ÞòÍ´¿³±ª·½¸ Û®·½ÐòÕª¿³ To the best of my knowledge and as understood by the student in the Thesis/Dissertation Agreement, Publication Delay, and Certification Disclaimer (Graduate School Form 32), this thesis/dissertation adheres to the provisions of Purdue University’s “Policy of Integrity in Research” and the use of copyright material. Approved by Major Professor(s): οµ»•¸ß¹®¿©¿´¿²¼Ý¿®±´ßòØ¿²¼©»®µ»® Approved by: Û´´·±¬¬ÞòÍ´¿³±ª·½¸ ïîñïñîðïë Head of the Departmental Graduate Program Date i SOLUTION ROUTES TO METAL CHALCOGNIDE AND ZINC OXIDE FOR DEVICE APPLICATIONS A Dissertation Submitted to the Faculty of Purdue University by Ruihong Zhang In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy i December 2015 Purdue University West Lafayette, Indiana ii For my parents. ii iii ACKNOWLEDGEMENTS I would like to thank my advisors, Prof. Carol Handwerker and Prof. Rakesh Agrawal who have given me enormous guidance and support on my research and course work during my doctorate program. By working with them closely, I was inspired by their enthusiasm in research, and learned how to approach a scientific problem and solve engineering problem efficiently. Under their guidance, I have also learned how to build collaboration and how to collaborate with researchers from different fields. They have always show full support on my new research ideas, encourage me to learn new knowledge and skill sets, and willingly share their ideas and perspectives. I am also grateful to my committee members, Prof. Elliott Slamovich and Prof. Eric Kvam. During my first project research work, I was working closely with Prof. Slamovich. He has provided me great guidance and constructive suggestions on the project. I have also enriched my knowledge in materials science and engineering by taking many of Prof. Kvam’s engaging classes and have held many great discussions regarding materials science with him. I also appreciate Prof. John Blendell, Prof. Mysore Dayananda, Prof. Eric Stach, and Prof. Kevin Trumble whom I have discussed specific research questions. I definitely have benefited a lot of from those discussions. I would also like to thank Vicki Cline, Patricia Finney, Donna Bystrom, and Melissa Laguire who iii have assisted me in many of the grueling administrative aspects during my doctorate program at the School of Materials Engineering. My graduate studies would not be successful without the collaboration and support from my great lab members: Dr. Wei-Chang D. Yang, Dr. Bryce Walker, Caleb Miskin, Dr. Charles Hages, Dr. Nathan Carter, Dr. Erik Sheets, Kevin Brew, Steve McLeod, Xin Zhao, Mark Koeper, iv Brian Graeser, Bobby Balow, Robert Boyne, Xianyi Hu, Dr. Hye Yeon Park, Scott Mclary, Chinmay Joglekar, and Bethlehem Negash. My research would not be efficient without the hard work and smart minds of my undergraduates: Stephen M. Szczepaniak, Daw Gen Lim, and Seonghyuk Cho. I would like to thank MSE colleague Dr. Wei-Hsun Chen, Dr. Pylin Sarobol, Luthfia Syarbaini, and Shu-han Hsu. I also appreciate having had the opportunity to work with Dr. Patricia Metcalf, Dr. Jiuning Hu, Dr. Sergey Suslov, Dr. Satoshi Ishii, Kim Kisslinger, Priya Murria, and Laurance Cain. I want to show my deepest appreciation to my parents for their endless love, encouragement, and support to my life, as well as their dedication to my education. I want to thank my families and friends for their love, understanding, support, and friendship. Lastly, I would like to thank the NSF Solar Economy IGERT program (0903670-DGE), DOE Sunshot Program (No. DE-EE0005328), and NSF-CMMI-0727960, GOALI. iv v TABLE OF CONTENTS .......... Page LIST OF TABLES ........................................................................................................................ viii LIST OF FIGURES ........................................................................................................................ ix ABSTRACT ............................................................................................................................. xviii CHAPTER 1. INTRODUCTION .................................................................................................... 1 1.1 Dissertation Organization .................................................................................................. 1 1.2 Principles of Solar Cell Operation .................................................................................... 3 1.3 Thin-Film Solar Cells ........................................................................................................ 6 1.4 CZTSSe Absorber Materials ............................................................................................. 7 1.5 Solution-Based Deposition Approaches .......................................................................... 10 CHAPTER 2. DEPOSITION OF CZTSSE THIN FILMS USING METAL SALT PRECURSOR SOLUTIONS .......................................................................................................... 12 2.1 Motivation ....................................................................................................................... 12 2.2 Review of Molecular Precursor Routes to CZTSSe Thin Films ..................................... 13 2.3 Experimental Section ...................................................................................................... 14 2.3.1 Molecular Precursor Preparation ........................................................................... 15 2.3.2 Film Deposition and Solvent Evaporation............................................................. 15 2.3.3 Selenization ........................................................................................................... 16 2.3.4 Device Fabrication ................................................................................................ 17 v 2.3.5 Characterization ..................................................................................................... 18 2.4 Results and Discussion .................................................................................................... 19 2.4.1 CZTSSe Molecular Precursor Solutions ............................................................... 19 2.4.2 Versatility of Primary Amine-Monothiol Solvent Mixtures ................................ 20 2.4.3 CZTSSe Solar Cells Processed from Butylamine-Propanethiol Based Precursor Solutions ................................................................................................................ 23 vi .......... Page 2.4.4 CZTSSe Solar Cells Processed from Hexyamine-Propanethiol Based Precursor Solutions ................................................................................................................ 29 2.4.5 Optimization of Cu Concentrations ....................................................................... 38 2.4.6 Solar Cells Processed from Different Metal Salts ................................................. 45 2.4.6.1 Solar Cells Processed from CuCl, ZnCl2, and Sn(acac)2Cl2 Precursor Solution ........................................................................................................... 45 2.4.6.2 Solar Cells Processed from CuCl2, ZnCl2, and SnCl2 Precursor Solution ....... 48 2.5 Conclusion....................................................................................................................... 52 CHAPTER 3. MICROSTRUCTURAL EVOLUTION DURING ANNEALING AND SELENIZATION .................................................................................................... 53 3.1 Introduction ..................................................................................................................... 53 3.2 Experimental Section ...................................................................................................... 53 3.3 Results and Discussion .................................................................................................... 54 3.3.1 Microstructure of Precursor Films......................................................................... 54 3.3.2 Phase Transformation during Selenization ............................................................ 55 3.3.3 Solar Cell Performance ......................................................................................... 60 3.4 Conclusion......................................................................................................................