Black silicon with tunnel oxide passivated contacts

Maren E. Kloster, Maria-Louise Witthøft, Denver C. Shearer, Alireza Hajijafarassar, Rasmus S. Davidsen, Dirch H. Petersen, Ole Hansen, Beniamino Iandolo

    Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

    108 Downloads (Pure)

    Abstract

    We investigate surfaces of black silicon (bSi) fabricated by reactive ion etch (RIE) on n-type Si substrates and passivated by in-situ doped polycrystalline Si (poly-Si) deposited by low pressure chemical vapor deposition (LPCVD). We achieved full surface coverage of bSi surfaces for poly-Si thickness of 20 nm. We determined sheet resistance on p-type and n-type poly-Si by means of micro four-point probe measurements. Effective lifetime mapping on symmetrically passivated samples shows that n-type poly-Si offers excellent surface passivation after hydrogenation, reaching effective lifetime values of almost 4 ms on non-textured substrates. P-type poly-Si shows values of effective lifetime lower than 800 μs and requires further improvement. We calculated i-Voc of up to 711 mV and 609 mV for asymmetrically passivated lifetime samples without texturing and with bSi, respectively. The effective lifetime is limited by the less-than-optimal passivation of the p-type poly-Si. Preliminary solar cell measurements indicate that both cell voltage and fill factor require major improvement on textured surfaces. Current work is directed towards the following goals: improving the quality of the p-type poly-Si; testing possible replacement of wet chemistry to grow the tunnel oxide using dry furnace oxidation; fabricating and comparing cells with p-n junction at the front or at the bottom of the cell.
    Original languageEnglish
    Title of host publicationProceedings of the 35th European Photovoltaic Solar Energy Conference and Exhibition
    Publication date2018
    Pages668-671
    ISBN (Electronic)3-936338-50-7
    DOIs
    Publication statusPublished - 2018
    Event35th European Photovoltaic Solar Energy Conference and Exhibition - Brussels, Belgium
    Duration: 24 Sep 201828 Sep 2018

    Conference

    Conference35th European Photovoltaic Solar Energy Conference and Exhibition
    CountryBelgium
    CityBrussels
    Period24/09/201828/09/2018

    Cite this

    Kloster, M. E., Witthøft, M-L., Shearer, D. C., Hajijafarassar, A., Davidsen, R. S., Petersen, D. H., ... Iandolo, B. (2018). Black silicon with tunnel oxide passivated contacts. In Proceedings of the 35th European Photovoltaic Solar Energy Conference and Exhibition (pp. 668-671) https://doi.org/10.4229/35thEUPVSEC20182018-2AV.3.19