ИСТИНА

Recently two approaches are considered as the most promising alternatives to bulk silicon solar cells, namely, concentrator technology as well as crystalline silicon thin film (cSiTF) solar cells consisting of a thin high qual-ity epitaxial layer on top of a highly doped substrate. In the present work we made an attempt to combine these two ap-proaches and to develop concentrator solar cell based on (n+np+)Cz-Si/Al cSiTF structure, at that using Laminated Grid Cell (LGCell) design of the contact system involving transparent electrode of Indium-Fluorine-Oxide (IFO) thin film and current collecting grid made of copper wire. The epitaxial layer of n-type silicon 50 μm thick was deposited on p+-Cz-Si type substrates with resistivity of ~0.01 Ω·cm, followed by texturing, phosphorus diffusion to create FSF and screen-printing of aluminum on the back. The best cSiTF LGCell from the first run fabricated using standard LGCell process demonstrated 16.1% efficiency at 1X and 16.75% at 4X. The standard LGCell design was revisited and optimized to re-duce the series resistance. The best cSiTF cell from the second run processed using modified LGCell process showed 15.9% efficiency at 1X and 17.0% at 10X. Furthermore, conventional LGCells based on IFO/(n+pp+)Cz-Si structure made of bulk silicon were also fabricated and tested under concentrated light. Conventional cells from the first run showed 19.0% efficiency at 1X, which monotonically reduces to 18% at 4X. However in the second run we obtained the cells which showed the increase of the efficiency with concentration from 18% at 1X up to 18.3-18.5% at 3-4X.