EPJ Photovoltaics 15, 24 (2024)
https://doi.org/10.1051/epjpv/2024007

Original Article

New approaches to edge passivation of laser cut PERC solar cells

¹ International Solar Energy Research Center (ISC) Konstanz, Rudolf-Diesel-Str. 15, 78467 Konstanz, Germany
² halm elektronik gmbh, Friesstraße 20, 60388 Frankfurt am Main, Germany

^* e-mail: akash.bhushan6@gmail.com

Received: 16 July 2023
Accepted: 18 January 2024
Published online: 17 June 2024

Abstract

Recently the development trend in the PV industry is towards much larger wafer formats. With increasing wafer area and the resulting increase in short-circuit current at the cell level, there is also a trend towards sub-cells (solar cell cut into smaller pieces) for module integration. Using sub-cells, the resistance losses through the connection can be reduced. Modules based on sub-cells achieve higher levels of fill factors and thus a higher nominal power. However, the energy yield of such sub-cells is reduced compared to full cells due to the non-passivated laser edge. The laser cut edge causes a high recombination of the charge carriers, which negatively affects the pseudo fill factor as well as open-circuit voltage of the cell. The current work introduces two different approaches for passivating the laser separated PERC solar cells. The experiments were performed on p-type PERC monofacial cells and laser scribe and mechanical cleavage (LSMC) technique was used to obtain sub-cells from the host cells. The method ‘laser scribing and simultaneous Al doping’ increases the pFF of the cleaved cells by +0.2–0.4%_abs in comparison to the reference cleaved cells whereas the method ‘laser scribing and subsequent Al doping’ shows an improvement in efficiency of the cleaved cells by + 0.2% _abs.