Morisset, AudreyFamprikis, TheodosiosHaug, Franz-JosefIngenito, AndreaBallif, ChristopheBannenberg, Lars J.2022-06-202022-06-202022-06-202022-04-1310.1021/acsami.2c01225https://infoscience.epfl.ch/handle/20.500.14299/188634WOS:000800533100051The integration of passivating contacts based on a highly doped polycrystalline silicon (poly-Si) layer on top of a thin silicon oxide (SiOx) layer has been identified as the next step to further increase the conversion efficiency of current mainstream crystalline silicon (c-Si) solar cells. However, the interrelation between the final properties of poly-Si/SiOx contacts and their fabrication process has not yet been fully unraveled, which is mostly due to the challenge of characterizing thin-film stacks with features in the nanometric range. Here, we apply in situ X-ray reflectometry and diffraction to investigate the multiscale (1 angstrom-100 nm) structural evolution of poly-Si contacts during annealing up to 900 degrees C. This allows us to quantify the densification and thinning of the poly-Si layer during annealing as well as to monitor the disruption of the thin SiOx layer at high temperature >800 degrees C. Moreover, results obtained on a broader range of thermal profiles, including firing with dwell times of a few seconds, emphasize the impact of high thermal budgets on poly-Si contacts' final properties and thus the importance of ensuring a good control of such high-temperature processes when fabricating c-Si solar cells integrating such passivating contacts. Overall, this study demonstrates the robustness of combining different X-ray elastic scattering techniques (here XRR and GIXRD), which present the unique advantage of being rapid, nondestructive, and applicable on a large sample area, to unravel the multiscale structural evolution of poly-Si contacts in situ during high-temperature processes.Nanoscience & NanotechnologyMaterials Science, MultidisciplinaryScience & Technology - Other TopicsMaterials Sciencec-si solar cellspassivating contactspoly-sisioxx-ray reflectometryin situ monitoringannealingrear contactsx-rayjunctionsqualitytext::journal::journal article::research article