Print Email Facebook Twitter The impact of processing conditions and post-deposition oxidation on the opto-electrical properties of hydrogenated amorphous and nano-crystalline Germanium films Title The impact of processing conditions and post-deposition oxidation on the opto-electrical properties of hydrogenated amorphous and nano-crystalline Germanium films Author de Vrijer, T. (TU Delft Photovoltaic Materials and Devices) Ravichandran, Ashwath (Student TU Delft) Bouazzata, Bilal (Student TU Delft) Smets, A.H.M. (TU Delft Photovoltaic Materials and Devices) Date 2021 Abstract Low-cost multijunction photovoltaic devices are the next step in the solar energy revolution. Adding a bottom junction with a low bandgap energy material through plasma enhanced chemical vapor deposition (PECVD) processing could potentially provide a low-cost boost in conversion efficiency. A logical candidate for this low bandgap material is germanium. In this work we investigate the growth of PECVD processed hydrogenated amorphous/nano-crystalline germanium (a/nc-Ge:H), by characterizing over 100 samples, processed with a wide range of deposition pressures, powers, temperatures and GeH4 dilution in hydrogen, using elemental analysis, vibrational analysis and analysis of the opto-electrical properties. We have identified a small processing window in which nc-Ge:H films are processed reproducibly. We also report on the strong correlation between the refractive index of the films and the presence- and extent of post-deposition oxidation. Notably, the oxidation generally increased the photoresponse of the films, as it results in a decrease of room temperature σd by 1-3 orders of magnitude. However, oxidation results in an increase of the bandgap energy and therefore impedes the development of a low bandgap material. The lowest E04 we report is about 1.1eV, with an ETauc of 0.9eV and an σph/σd of 3.4. Subject a-Ge:Hgermaniumgermanium oxidenanocrystallineoxidationPECVD To reference this document use: http://resolver.tudelft.nl/uuid:a4212dc5-b0ce-4a4e-9a79-b8e93c41189c DOI https://doi.org/10.1016/j.jnoncrysol.2020.120507 ISSN 0022-3093 Source Journal of Non-Crystalline Solids, 553, 1-9 Part of collection Institutional Repository Document type journal article Rights © 2021 T. de Vrijer, Ashwath Ravichandran, Bilal Bouazzata, A.H.M. Smets Files PDF 1_s2.0_S0022309320306177_main.pdf 2.53 MB Close viewer /islandora/object/uuid:a4212dc5-b0ce-4a4e-9a79-b8e93c41189c/datastream/OBJ/view