Toward Annealing-Stable Molybdenum-Oxide-Based Hole-Selective Contacts For Silicon Photovoltaics
De Wolf, Stefaan
KAUST DepartmentPhysical Sciences and Engineering (PSE) Division
Materials Science and Engineering Program
KAUST Solar Center (KSC)
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AbstractMolybdenum oxide (MoOX) combines a high work function with broadband optical transparency. Sandwiched between a hydrogenated intrinsic amorphous silicon passivation layer and a transparent conductive oxide, this material allows a highly efficient hole-selective front contact stack for crystalline silicon solar cells. However, hole extraction from the Si wafer and transport through this stack degrades upon annealing at 190 °C, which is needed to cure the screen-printed Ag metallization applied to typical Si solar cells. Here, we show that effusion of hydrogen from the adjacent layers is a likely cause for this degradation, highlighting the need for hydrogen-lean passivation layers when using such metal-oxide-based carrier-selective contacts. Pre-MoOX-deposition annealing of the passivating a-Si:H layer is shown to be a straightforward approach to manufacturing MoOX-based devices with high fill factors using screen-printed metallization cured at 190 °C.
CitationEssig S, Dréon J, Rucavado E, Mews M, Koida T, et al. (2018) Toward Annealing-Stable Molybdenum-Oxide-Based Hole-Selective Contacts For Silicon Photovoltaics. Solar RRL: 1700227. Available: http://dx.doi.org/10.1002/solr.201700227.
SponsorsThe authors would like to thank Raphaël Monnard and Guillaume Charitat from EPFL and Nicolas Badel, Silvia Martin de Nicolas and Fabien Debrot from CSEM for work performed in the context of this publication. Furthermore, we thank Davide Sacchetto and Sylvain Nicolay from CSEM, and Andres Cuevas from ANU for discussions, Virginia Unkefer from KAUST for manuscript editing. S. Essig held a Marie Skłodowska-Curie Individual Fellowship from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No: 706744, action acronym: COLIBRI). Part of this work was funded by the European Union's Horizon 2020 research and innovation programme under Grant Agreements no. 727529 (project DISC), and by the Swiss National Science Foundation via the NRP70 “Energy Turnaround” project “PV2050.”