Flexible, Lightweight Solar Cell with 40% Efficiency Fabricated by Epitaxial Liftoff and Wafer Bonding

MicroLink Devicesproposes to develop an ultra-high efficiency, radiation-hard, six-junction solar cell for application to Air Force space missions. The proposed technology will comprise lattice-matched subcells grown on InP and GaAs substrates that are mechanically attached in a monolithic structure to achieve 1-sun AM0 efficiency in excess of 40%. To render the solar cell cost-efficient, epitaxial lift-off (ELO) will be used to separate the epitaxial layers from the InP substrate, allowing it to be reused for multiple growth cycles. The thin epitaxial layers will be attached to the back of the GaAs substrate in the final device structure using an epoxy bonding process. Dr. Messenger, a pioneer in the field of radiation modeling, will perform realistic environment simulations for missions in GEO, MEO and LEO, and the solar cell structure will be optimized for performance in the relevant mission radiation environment.