Thin-film GaAs solar cells by epitaxial lift-off

The authors have performed basic characterization studies of thin-film GaAs n/p and p/n solar cells made by epitaxial lift-off. They find that the internal quantum efficiency is enhanced by as much as 71% in these cells after lift-off due to the presence of a back reflector. An unalloyed, low series resistance back contact can be made with proper contacting techniques and using only van der Waals bonding to gold or palladium. These preliminary results show that thin-film solar cells can be processed without loss of film quality, and suggest that successful implementation of this design concept should lead to increased conversion efficiencies.<
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