Insights in light trapping for new generation silicon solar cell: optical characterization of plasmonic nanostructures beside anti-reflection layer

Abstract

Designing light-trapping is one of the requirements for new generation silicon solar cells. Herein, the optical properties of front-based plasmonic nanoparticles besides the anti-reflection layer on new-generation silicon cells were investigated by the 3D-FDTD method and were compared with some experimental kinds of literature. In addition to a perfectly periodic structure, the almost periodic structure (closer to the experimental sample) was also modeled. Along with the conventional far and near-field effect, the spectral normalized enhancement parameter to the standard cell (g-curve) and its weighted to AM 1.5 and spectral integrated (G-value) were used as a suitable characterizing set. The results showed that the g-curve of the sample with the anti-reflection layer showed superiority compared to the standard cell on the ~ full wavelength range. Moreover, the thickness engineering of the anti-reflection layer can itself significantly increase cell performance (G=1.4). In contrast, the g-curve of some optimum plasmonic samples below 500 nm wavelength was not significantly effective. The best G-value among plasmonic samples was 1.3. Also, the combination of anti-reflection and plasmonic design did not lead to significant improvement not only for perfect periodic samples but also for nonperfect ones. The obtained results determined that the plasmonic system can lead to a considerable decrease in spectral reflectance, consistent with some reported experimental ones. Moreover, the simulations clarified the cause of plasmonic failure in some experimental studies that due to the lateral trap of the light, this reduction in reflection does not lead to directing near and far-field into the active layer.