Flexible and lightweight epitaxial lift-off GaAs multi-junction solar cells for portable power and UAV applications

Epitaxial lift-off (ELO) is a process technology that can enable substantial performance enhancement and cost reduction for epitaxially grown III-V devices. [1]-[4] In particular, GaAs-based inverted metamorphic multijunction (IMM) solar cells are an attractive technology that provides flexible, light-weight and high-efficiency solar panels for portable-power and unmanned aerial vehicle (UAV) applications. ELO is a process that involves selectively etching a “release” layer to detach the epitaxially grown functional III-V material from the substrate on which it is grown. The flexible ELO solar cell device layers are temporarily mounted on rigid carriers for standard, high-volume semiconductor processing methods, followed by release and integration into flexible panel formats.