The cleavage of lateral epitaxial films for transfer or CLEFT is a method for producing low-cost Gallium Arsenide (GaAs) photovoltaic cells in which a thin film of GaAs is grown on top of a thick, single-crystal GaAs (or other suitable material) substrate and is then separated from the substrate and integrated into a cell, allowing the substrate to be reused for the growth of additional thin films of GaAs.
How CLEFT Helps Create Extra Cells?
Growing extremely thin gallium arsenide is part of the CLEFT (cleavage of lateral epitaxial films for transfer) technique (GaAs solar cell on a much thicker layer of the same material). A solar cell can be easily separated when the growth process is finished by cleaving from a much thicker substrate. A thick substrate can be used to create extra cells, which lowers the price of cell material.
What is the Future of CLEFT?
GaAs CLEFT single-crystal layers with 2-in diameters and less than 10 microns in thickness have been created. Recent developments in substrate preparation and growth technologies allowed the CLEFT method to be scaled up to entire 2-inch round wafers. A 2-inch layer of solar cell structures has been created and simultaneously removed from the substrate. This innovation raises the likelihood of creating highly effective thin-film solar cells for extensive terrestrial applications. The only reason for the current size restriction is the epitaxial apparatus currently in use for this work. It is believed that larger diameter CLEFT layers are easily realizable.
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