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The use of porous silicon layers in thin‐film silicon solar cells
Author(s) -
Van Hoeymissen Jan,
Depauw Valerie,
KuzmaFilipek Izabela,
Van Nieuwenhuysen Kris,
Payo Maria Recaman,
Qiu Yu,
Gordon Ivan,
Poortmans Jef
Publication year - 2011
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201000103
Subject(s) - materials science , solar cell , passivation , epitaxy , optoelectronics , silicon , thin film , layer (electronics) , crystalline silicon , quantum dot solar cell , porous silicon , substrate (aquarium) , monocrystalline silicon , annealing (glass) , nanotechnology , composite material , oceanography , geology
In the quest for lowering the manufacturing cost of silicon solar cells, imec has been working successfully on two crystalline Si ‘thin‐film’ cell concepts. In a first concept, a 20 µm‐thin Si solar cell is epitaxially grown on top of a porous Si‐based Bragg‐type reflector which is electrochemically etched in a low‐cost UMG Si substrate. Large area solar cells with efficiencies of 15.2% have been made, using (semi‐)industrial processing tools. This clearly demonstrates that this cell concept has almost reached the stage of industrial application. In a second, longer‐term approach, a 1–5 µm‐thin, stand‐alone mono‐crystalline film is created based on the controlled annealing of an ordered macroporous silicon layer (the ‘Epi‐free’ process). With this very thin Si layer, a simple proof‐of‐concept solar cell has been made exhibiting an efficiency of 4%. By optimizing the cell process in terms of light trapping and passivation, efficiencies over 15% can be expected from this technology.