Wet-Chemical Preparation of Silicon Tunnel Oxides for Transparent Passivated Contacts in Crystalline Silicon Solar Cells

Malte Köhler; Manuel Pomaska; Florian Lentz; Friedhelm Finger; Uwe Rau; Kaining Ding

doi:10.1021/acsami.8b02002

Wet-Chemical Preparation of Silicon Tunnel Oxides for Transparent Passivated Contacts in Crystalline Silicon Solar Cells

ACS Appl Mater Interfaces. 2018 May 2;10(17):14259-14263. doi: 10.1021/acsami.8b02002. Epub 2018 Apr 23.

Authors

Malte Köhler¹, Manuel Pomaska¹, Florian Lentz¹, Friedhelm Finger¹, Uwe Rau¹, Kaining Ding¹

Affiliation

¹ IEK-5 Photovoltaik, Forschungszentrum Jülich GmbH , 52425 Jülich , Germany.

PMID: 29664611
DOI: 10.1021/acsami.8b02002

Abstract

Transparent passivated contacts (TPCs) using a wide band gap microcrystalline silicon carbide (μc-SiC:H(n)), silicon tunnel oxide (SiO₂) stack are an alternative to amorphous silicon-based contacts for the front side of silicon heterojunction solar cells. In a systematic study of the μc-SiC:H(n)/SiO₂/c-Si contact, we investigated selected wet-chemical oxidation methods for the formation of ultrathin SiO₂, in order to passivate the silicon surface while ensuring a low contact resistivity. By tuning the SiO₂ properties, implied open-circuit voltages of 714 mV and contact resistivities of 32 mΩ cm² were achieved using μc-SiC:H(n)/SiO₂/c-Si as transparent passivated contacts.

Keywords: passivated contact; selective contact; silicon carbide (SiC); silicon oxide (SiO2); silicon surface passivation; transparent passivated contact (TPC); tunnel oxide; wet-chemical oxidation.