Efficient Light Management in Ultrathin Crystalline GaAs Solar Cell Based on Plasmonic Square Nanoring Arrays

Improving the photon absorption in ultrathin-film solar cells with active layer thickness of a few micrometers is important for enhancing efficiency and reducing cost. We present a computational study of novel design consisting of ultrathin absorber layer made of gallium arsenide (GaAs) integrated with plasmonic square nanoring particles. The energy absorbed by GaAs layer is significantly enhanced with the help of plasmonic nanorings, resulting in substantial absorption enhancement of approximately 34% compared with bare active layer. For qualitative analysis, the short-circuit current density of thin-film cell is evaluated for AM 1.5 G solar illumination and is found to be 1.4 times higher compared with unpatterned solar cell structure. Furthermore, the structure is optimized by varying different parameters and materials of functional layers, yielding a photocurrent density of 30.185 mA/cm(2), which is close to the Yablonovitch limit.