P-type nc-SiOx:H emitter layer for silicon heterojunction solar cells grown by RF-PECVD

Autor: Gatz, H.A., Kuang, Y., Verheijen, M.A., Rath, J.K., Kessels, W.M.M., Schropp, R.E.I., Hekmatshoar, B., Collins, R.
Přispěvatelé: Plasma & Materials Processing, Atomic scale processing, Processing of low-dimensional nanomaterials
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Zdroj: Material Research Society (MRS) Proceedings
Popis: Silicon heterojunction solar cells (SHJ) with thin intrinsic layers are well known for their high efficiencies. A promising way to further enhance their excellent characteristics is to enable more light to enter the crystalline silicon (c-Si) absorber of the cell while maintaining a simple cell configuration. Our approach is to replace the amorphous silicon (a-Si:H) emitter layer with a more transparent nanocrystalline silicon oxide (nc-SiOx:H) layer. In this work, we focus on optimizing the p-type nc-SiOx:H material properties, grown by radio frequency plasma enhanced chemical vapor deposition (rf PECVD), on an amorphous silicon layer.20 nm thick nanocrystalline layers were successfully grown on a 5 nm a-Si:H layer. The effect of different ratios of trimethylboron to silane gas flow rates on the material properties were investigated, yielding an optimized material with a conductivity in the lateral direction of 7.9×10-4 S/cm combined with a band gap of E04 = 2.33 eV. Despite its larger thickness as compared to a conventional window a-Si:H p-layer, the novel layer stack of a-Si:H(i)/nc-SiOx:H(p) shows significantly enhanced transmission compared to the stack with a conventional a-Si:H(p) emitter. Altogether, the chosen material exhibits promising characteristics for implementation in SHJ solar cells.
Databáze: OpenAIRE