Practice for the EPVSEC --- LASER-ASSISTED SHUNT REMOVAL ON HIGH-EFFICIENCY SILICON SOLAR CELLS

Dr Ngwe-Soe Zin, Kelvin Sio and Peter (Research School of Engineering)

SOLAR SEMINAR SERIES

DATE: 2012-09-18
TIME: 16:00:00 - 17:00:00
LOCATION: Ian Ross Seminar Room
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ABSTRACT:
Soe Zin and two Ph.D students will give there talks before the present them to the European PV and Solar Energy Conference the following week in Frankfurt.

Development of all-back-contact (ABC) silicon solar cells at the Australian National University (ANU), as part of a collaboration between Trina Solar and the Solar Energy Research Institute of Singapore (SERIS), is progressing, and 22.1% efficient ABC cells, based on the aperture-area of 13 cm2 that excludes busbars, were recently fabricated at ANU. When measured using the 16 cm2 aperture-area that includes busbars, the cells are 21.6% efficient. In this paper, we demonstrate the technique of removing shunts, associated in the development of ABC cells, by laser-assisted means. The laser that we use for the shunt removal is 532 nm diode pump solid state (DPSS) laser. The shunts are caused by residual boron (p+) diffusion within the phosphorus (n+) diffused region following the trench etch that separates the p and n regions. Photoluminescence (PL) imaging showed that apparent shunt regions were removed following this process. Analysis of ABC solar cells by dark IV characterisation further confirmed that the shunt resistance was increased by about 30-fold (350 to 11500 I.cm2). The effective removal of shunts has increased the cell efficiency by 0.5% absolute. Carrier recombination induced by laser damage appears to be minimal since open-circuit voltage of the ABC cells barely changes for pre- and post-laser ablation, although more detailed investigations are required.

For Kelvin and Peter, titles and abstract were not supplied
BIO: