Transfer of InGaP/GaAs double-junction micro-cuboid array onto foreign substrates using epitaxial lift-off (ELO) technique

As a result of the ability to tune the band-gap of III-V compound semiconductor materials to match the solar spectrum, solar cells made from II -V materials such as GaAs and InGaP have unsurpassed conversion efficiencies. However, after the deposition of the solar cell film, the substrate is of no further use for its performance. The reduction of the costs of III-V semiconductor materials and the increase of the power to weight ratio are highly desired. The most successful method to achieve these goals is epitaxial lift-off (ELO). In order to shorten the ELO etching time and prevent the microscopic cleavage cracks, the authors develop a unique transplantation method. The steps in this technique were presented in this paper.