Development of a rapid thermal annealing process for polycrystalline silicon thin-film solar cells on glass

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Vol. 159; pp. 329 - 332
• Main Authors: Rau, B., Weber, T., Gorka, B., Dogan, P., Fenske, F., Lee, K.Y., Gall, S., Rech, B.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.03.2009
• Subjects: Annealing; Glass; Hydrogen; Silicon; Solar cells; Thin films; Thin films; Solar cells; Annealing; Silicon; Hydrogen; Glass
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2008.05.007

In this report, we discuss the influence of rapid thermal annealing (RTA) on the performance of polycrystalline Si (poly-Si) thin-film solar cells on glass where the poly-Si layers are differently prepared. The first part presents a comprehensive study of RTA treatments on poly-Si thin-films made by solid phase crystallization (SPC) (standard material of CSG Solar AG, Thalheim). By varying both plateau temperature (up to 1050 °C) and duration (up to 1000 s) of the annealing profile, we determined the parameters for a maximum open-circuit voltage ( V OC). In addition, we applied our standard plasma hydrogenation treatment in order to passivate the remaining intra-grain defects and grain boundaries by atomic hydrogen resulting in a further increase of V OC. We found, that the preceding RTA treatment increases the effect of hydrogenation already at comparable low RTA temperatures. The effect on hydrogenation increases significantly with RTA temperature. In a second step we investigated the effect of the RTA and hydrogenation on large-grained poly-Si films based on the epitaxial thickening of poly-Si seed layers.