Hydrogenated polymorphous silicon: establishing the link between hydrogen microstructure and irreversible solar cell kinetics during light soaking Ka-Hyun Kim To cite this version: Ka-Hyun Kim. Hydrogenated polymorphous silicon: establishing the link between hydrogen mi- crostructure and irreversible solar cell kinetics during light soaking. Materials Science [cond-mat.mtrl- sci]. Ecole Polytechnique X, 2012. English. pastel-00747463 HAL Id: pastel-00747463 https://pastel.archives-ouvertes.fr/pastel-00747463 Submitted on 31 Oct 2012 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Doctoral thesis in Physics / Materials Science Hydrogenated polymorphous silicon: establishing the link between hydrogen microstructure and irreversible solar cell kinetics during light soaking Ka-Hyun Kim THÈSE Présentée en vue d’obtenir le grade de Docteur de l’École Polytechnique Spécialité : Physique / Science des Matériaux par Ka-Hyun Kim Hydrogenated polymorphous silicon: establishing the link between hydrogen microstructure and irreversible solar cell kinetics during light soaking Thèse soutenue le 9 Octobre 2012 devant le jury compose de : Prof. Anna Fontcuberta i Morral Rapporteur Prof. Laifa Boufendi Rapporteur Dr. Friedhelm Finger Examinateur Dr. Edward A. G. Hamers Examinateur Dr. Lars Oberbeck Examinateur Dr. René A.C.M.M. van Swaaij Examinateur Prof. Pere Roca i Cabarrocas Directeur de thèse Dr. Erik V. Johnson Co-directeur de thèse Acknowledgments For the past three years, this thesis would not have been possible without the support of many people. I thank to Vincent Schachter, Marc Vermeersch, and Loïc Francke for welcoming me into TOTAL-LPICM joint research team and for supporting from industry side. I thank to Lars Oberbeck for accepting jury for my PhD defense and continuous supporting. I deeply appreciate all the members of juries, Prof. Anna Fontcuberta i Morral, Prof. Laifa Boufendi, Friedhelm Finger, Edward A. G. Hamers, and René A.C.M.M. van Swaaij. The deepest gratitude is due to my director, Prof. Pere Roca i Cabarrocas for his invaluable support and guidance. I also express my gratitude to Prof. Jin Jang, Prof. Yvan Bonnassieux, Erik V. Johnson, Samir Kasouit, and Alexey Abramov. Since my master program, they have been my mentors and directors, and it is impossible to imagine my PhD thesis without their help, support and guidance. I am proud of that I am one of the earliest members of TOTAL- LPICM joint research team, and I appreciate everyone in “les algecos”, Martin Labrune, Antoine Salomon, Patricia Prod'homme, Jérôme Damon- Lacoste, Coralie Charpentier, Jean-Francois Besnier, Ludovic Hudanski, Guillaume Courtois, Nada Habka, Jean-Christophe Dornstetter, Igor Sobkowicz, and Bastien Bruneau. I confess that les algecos have been the world’s happiest and the funniest workplace thank to those colleagues. I am grateful to Benedict O'Donnell, Romain Cariou, Alfonso Torres- Rios, Changseok Lee, Kihwan Kim, Jinyoun Cho, Mun-Ho Song, Taewoo Jeon, Chang-Hyun Kim, Jongwoo Jin, Youn-Ho Heo, Pavel Bulkin, Tatiana Novikova, Rosa Ruggeri, Sofia Gaiaschi, Rym Boukhicha, Parsathi Chatterjee, Dmitri Daineka, Bicher Haj Ibrahim, Sergey Abolmasov, Maher Oudwan, Mario Moreno, Sanjay Ram, Linwei Yu, and Junzhuan Wang, with whose great knowledge, literature and discussion, my PhD thesis could be completed. Also special thanks to all laboratory members, Rosaria Antonelli, Laurent Baraton, Rachida Boubekri, Jean-Eric Bouree, Marc Chaigneau, Jerome Charliac, Frederic Farci, Enric Garcia-Caurel, Bernard Geffroy, Cyril ix Jadaud, Laurent Kroely, Emmanuel Lefeuvre, Frederic Liege, Joaquim Nassar, Razvigor Ossikovski, Eric Paillassa, Jacqueline Samson, Denis Tondelier, Holger Vach, Jean-Charles Vanel, Omid Yaghmazadeh, Joonwon Lim, Yong-Bin Jeong, Myung-Jin Lim, Taeha Hwang, Kihwan Seok, Jinwoo Choi, Hojoong Kwon, Sungyeop Jung, and Heechul Woo. At last, I wish to express my love and gratitude to my beloved family and ma chérie, Kyoungsoon. x Contents Acknowledgments ................................................................................. ix Contents ................................................................................................ xi List of Figures .....................................................................................xiii List of Tables ...................................................................................... xix List of Abbreviations and Symbols .................................................... xxi Chapter 1 – Backgrounds ..................................................................... 23 1.1 Introduction ....................................................................................................... 24 1.2 Plasma enhanced chemical vapor deposition .................................................. 24 1.3 Hydrogenated amorphous silicon ..................................................................... 27 1.4 Staebler-Wronski effect .................................................................................... 28 1.5 Hydrogenated polymorphous silicon ................................................................ 31 1.6 Material and device characterization .............................................................. 33 1.6.1 Spectroscopic Ellipsometry and Modelling ......................................................... 35 1.6.2 UV-VIS Transmission-Reflection ........................................................................36 1.6.3 Sub-gap absorption measurements .....................................................................38 1.6.4 Fourier transform infrared spectroscopy ............................................................39 1.6.5 Hydrogen exodiffusion .........................................................................................41 1.6.6 Dark conductivity .................................................................................................42 1.6.7 Atomic Force Microscopy and Scanning Electron Microscopy ........................... 44 1.6.8 Diode dark J(V) ....................................................................................................46 1.6.9 Solar cell parameters ...........................................................................................48 Chapter 2 – Hydrogenated Polymorphous Silicon – Material ............ 54 2.1 Introduction ....................................................................................................... 56 2.2 ARCAM reactor ................................................................................................. 56 2.3 a-Si:H and pm-Si:H deposition ......................................................................... 59 2.4 Gas flow rate series ........................................................................................... 67 2.5 Pressure series .................................................................................................. 70 2.6 RF power series ................................................................................................. 74 2.7 Ts series ............................................................................................................. 79 2.8 Powder formation and residence time ............................................................. 85 xi 2.9 Summary ........................................................................................................... 89 Chapter 3 – Hydrogenated Polymorphous Silicon Solar Cells ........... 97 3.1 Introduction ....................................................................................................... 98 3.2 Standard PIN solar cells ................................................................................... 98 3.3 Effect of light-trapping ................................................................................... 106 3.4 Intrinsic layer optimization ............................................................................ 107 3.5 HR pm-Si:H PIN solar cells ............................................................................ 113 3.6 Stability issues of PIN solar cells ................................................................... 119 3.7 Summary ......................................................................................................... 123 Chapter 4 – Light-Induced Degradation and Solar Cell Stability ... 125 4.1 Introduction ..................................................................................................... 126 4.2 PIN solar cell device stability – initial behavior ........................................... 126 4.3 Light-induced structural changes .................................................................. 144 4.4 Light-induced hydrogen motion ..................................................................... 160 4.5 Hypothesis on light-induced changes ............................................................ 171 4.6 Long-term stability and new device structure .............................................. 174 4.7 Summary ........................................................................................................