Investigation of High-Efficiency Screen-Printed Textured SI Solar Cells with High Sheet-Resistance Emitters
Date
2005-01Author
Hilali, Mohamed M.
Nakayashiki, Kenta
Ebong, Abasifreke
Rohatgi, Ajeet
Metadata
Show full item recordAbstract
In this study it is found that the efficiency
enhancement (Δη) resulting from the use of a 100 Ω/sq emitter instead of a conventional 45 Ω/sq emitter is substantially enhanced further by surface texturing. This enhancement is greater for textured cells by at least ~0.4% absolute over the enhancement for planar cells, and is mainly due to the greater difference in the front-surface
recombination velocity (FSRV) between the high and low-sheet-resistance emitter textured cells. A FSRV of 60,000 cm/s resulted in a reasonably good V(oc) of ~642
mV for the 100 Ω/sq emitter textured cell. Our investigation of the Ag-Si contact interface shows a more regular distribution of Ag crystallite precipitation for the
textured emitter (mainly at the peaks of the texture pyramids). The high contact-quality resulted in a series resistance of 0.79 Ω-cm, a junction leakage current of 18.5 nA/cm(2) yielding a FF of 0.784. This resulted in a record high-efficiency 4 cm(2) screen-printed cell of 18.8% (confirmed by NREL) on textured 0.6 Ω-cm FZ, with
single-layer antireflection coating.