Large area, thin film epitaxial lift off III/V solar cells

The epitaxial lift-off (ELO) method is generally considered to be very suitable for separation of a thin epilayer from its substrate. The method is very gentle and hardly effects the substrate. Here, the authors present improvements and modifications on this method resulting in successful separation of crack-free thin-films as large as 2 inch substrates. The roughness of the substrates after the ELO and the quality of epilayers after growth on used substrates was determined in order to investigate the re-use of the substrates. As a demonstration of the capability of this modified ELO procedure, a thin film GaAs/AlGaAs solar cell made by this method is presented.