Print Email Facebook Twitter Poly-crystalline silicon-oxide films as carrier-selective passivating contacts for c-Si solar cells Title Poly-crystalline silicon-oxide films as carrier-selective passivating contacts for c-Si solar cells Author Yang, G. (TU Delft Photovoltaic Materials and Devices) Guo, Peiqing (Student TU Delft) Procel Moya, P.A. (TU Delft Photovoltaic Materials and Devices) Weeber, A.W. (TU Delft Photovoltaic Materials and Devices; ECN, Petten) Isabella, O. (TU Delft Photovoltaic Materials and Devices) Zeman, M. (TU Delft Electrical Sustainable Energy) Department Electrical Sustainable Energy Date 2018 Abstract The poly-Si carrier-selective passivating contacts (CSPCs) parasitically absorb a substantial amount of light, especially in the form of free carrier absorption. To minimize these losses, we developed CSPCs based on oxygen-alloyed poly-Si (poly-SiOx) and deployed them in c-Si solar cells. Transmission electron microscopy analysis indicates the presence of nanometer-scale silicon crystals within such poly-SiOx layers. By varying the O content during material deposition, we can manipulate the crystallinity of the poly-SiOx material and its absorption coefficient. Also, depending on the O content, the bandgap of the poly-SiOx material can be widened, making it transparent for longer wavelength light. Thus, we optimized the O alloying, doping, annealing, and hydrogenation conditions. As a result, an extremely high passivation quality for both n-type poly-SiOx (J0 = 3.0 fA/cm2 and iVoc = 740 mV) and p-type poly-SiOx (J0 = 17.0 fA/cm2 and iVoc = 700 mV) is obtained. A fill factor of 83.5% is measured in front/back-contacted solar cells with both polarities made up of poly-SiOx. This indicates that the carrier transport through the junction between poly-SiOx and c-Si is sufficiently efficient. To demonstrate the merit of poly-SiOx layers' high transparency at long wavelengths, they are deployed at the back side of interdigitated back-contacted (IBC) solar cells. A preliminary cell efficiency of 19.7% is obtained with much room for further improvement. Compared to an IBC solar cell with poly-Si CSPCs, a higher internal quantum efficiency at long wavelengths is observed for the IBC solar cell with poly-SiOx CSPCs, thus demonstrating the potential of poly-SiOx in enabling higher JSC. To reference this document use: http://resolver.tudelft.nl/uuid:a36fdf28-a85f-4a2a-8ef3-f2064bdbc419 DOI https://doi.org/10.1063/1.5027547 ISSN 0003-6951 Source Applied Physics Letters, 112 (19), 1-6 Bibliographical note Accepted Author Manuscript Part of collection Institutional Repository Document type journal article Rights © 2018 G. Yang, Peiqing Guo, P.A. Procel Moya, A.W. Weeber, O. Isabella, M. Zeman Files PDF 45255258_Poly_crystalline ... _cells.pdf 401.75 KB Close viewer /islandora/object/uuid:a36fdf28-a85f-4a2a-8ef3-f2064bdbc419/datastream/OBJ/view