Light weight flexible solar cells performance enhanced with nanostructures

In the proposed Phase I project, MicroLink and its subcontractor, the University of Texas at Austin, will increase the integrated energy generated over an entire day by employing novel periodic optical nano patterns to optimize light propagation and absorption in epitaxial lift-off (ELO) GaAs solar cells.These nanostructures will enhance the absorption and trapping of light by minimizing surface reflectance and altering light propagation paths to increase optical absorption, particularly for longer wavelengths for which optical absorption coefficients are low.Flexible GaAs ELO solar cells employing optical nanostructures can dramatically outperform the existing II-VI based solar cells such as CIGS and CdTe, or a-Si:H.Photon recycling will be implemented by applying back surface reflectors combined with 2D dielectric gratings, which are ideal for thin ELO solar cells.The nano texturing will be incorporated using thin-film material layers typically employed as antireflection layers to ensure compatibility with existing fabrication processes.At the end of Phase I we will deliver flexible GaAs solar cells with overall energy >25W/lb.In the Phase I Option, MicroLink will develop and deliver a lightweight, high-efficiency, flexible GaAs based solar sheet for use in mobile solar power applications.