EL and LBIC characterization of cut edge recombination in IBC solar cells

Bokalič, Matevž (author), Kikelj, Miha (author), Brecl, Kristijan (author), Jankovec, Marko (author), Buchholz, Florian (author), Mihailetchi, Valentin (author), Topič, Marko (author)

The interconnection of cut cells is a way to improve cell to module efficiency ratio. While this approach minimizes series resistance losses and improves module area utilization, it introduces recombination losses due to imperfect cuts. We propose two additional methods to characterize edge recombination based on multi-wavelength light beam induced current (LBIC) measurements and current-dependent spatially resolved electroluminescence (EL). We test the methods on interdigitated back contact silicon solar cells, which were cut in our laboratory using a not yet optimized procedure with laser ablation and mechanical cleaving. The proposed LBIC based measurement offers an easy interpretation as its result can be directly linked to the local external quantum efficiency, while the proposed EL method can be used as an alternative to the established PL methods without the need of a light source. The results show a clear distinction between cut and uncut edges, which was observed with both methods. The influence of edge recombination is still evident 2 mm away from the cell edge in the EL measurements, and 1 mm and 0.5 mm in the LBIC measurements at 1060 and 642 nm, respectively. For the uncut edge the influence is smaller. Based on the LBIC measurements, the EQE loss at the cut edge is estimated to be 9% for a 1 mm and 0.5 mm wide area along the edge for 1060 and 642 nm, respectively. We also observed a non-intuitive EL behaviour, since the EL signal obtained with high current bias decreases faster towards the edge than the EL signal obtained with low bias current. Similarly, a difference between normalized LBIC profiles is observed at different wavelengths. For the uncut edge, the LBIC signal has a slightly steeper response at 1060 nm than at 642 nm.

• Language: English
• Keywords: electroluminescence, LBIC, edge recombination, IBC, silicon solar cells
• Typology: 1.08 - Published Scientific Conference Contribution
• Organization: FE - Faculty of Electrical Engineering
• Publication status: Published
• Publication version: Author Accepted Manuscript
• Year: 2020
• Number of pages: Str. 308-311
• PID: 20.500.12556/RUL-134032
• UDC: 621.383.51
• ISSN on article: 2196-100X
• DOI: 10.4229/EUPVSEC20202020-2CV.1.9
• COBISS.SI-ID: 58036483
• Publication date in RUL: 22.12.2021

Record is a part of a proceedings

• Title: 37th European Photovoltaic Solar Energy Conference and Exhibition
• COBISS.SI-ID: 36337923

Record is a part of a journal

• Title: Proceedings
• Publisher: WIP, Wirtschaft und Infrastruktur GmbH & Co Planungs KG
• ISSN: 2196-100X
• COBISS.SI-ID: 10276692

Secondary language

• Language: Slovenian
• Keywords: elektroluminiscenca, LBIC, rekombinacija na robu, IBC, prepleteni zadnji kontakti, multikristalni silicij, sončne celice

Projects

• Funder: EC - European Commission
• Funding programme: H2020
• Project number: 857793
• Name: High-performance low-cost modules with excellent environmental profiles for a competitive EU PV manufacturing industry
• Acronym: HighLite

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0197
• Name: Fotovoltaika in elektronika