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Title: Controlling Pinhole Radius and Areal Density in a-Si/SiOx Using Metal-Assisted Chemical Etching

Conference ·
DOI:https://doi.org/10.1063/5.0089213· OSTI ID:1890130

Polysilicon on silicon oxide (poly-Si/SiOx) passivating contacts with predominant charge-carrier transport via pinholes are currently prepared via a>1000 degrees C thermal step to induce oxide break-up. Herein, we develop the precursor of a pinhole-enabled poly-Si/SiOx contact utilizing room temperature metal-assisted chemical etching (MACE) to form pinholes in the SiOx. The pinholes were created via electroless Ag nanoparticle (Ag NP) deposition followed by the MACE of intrinsic amorphous hydrogenated silicon (a-Si:H) on SiOx, creating isolated mesopores through the film stack. By varying the MACE etching solution (HF:H2O2) concentration, we were able to vary the pinhole areal density over four orders of magnitude (104-107 cm-2). We observed the Ostwald ripening of the Ag NP to enable control over the pinhole radii. Our work demonstrates proof-of-concept for a-Si:H/SiOx with mesopores across the film stack, which may serve as precursor for the development of poly-Si/SiOx passivating contacts of both polarities.

Research Organization:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
DOE Contract Number:
AC36-08GO28308
OSTI ID:
1890130
Report Number(s):
NREL/CP-5900-79903; MainId:39121; UUID:78da00db-22ef-4a01-ba01-7be23159f0ec; MainAdminID:23474
Resource Relation:
Conference: Presented at SiliconPV 2021: The 11th International Conference on Crystalline Silicon Photovoltaics, 19-23 April 2021, Hamelin, Germany
Country of Publication:
United States
Language:
English

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