%0 Journal Article
%T Nano-Photonic Structures for Light Trapping in Ultra-Thin Crystalline Silicon Solar Cells
%A Akshit Peer
%A Prathap Pathi
%A Rana Biswas
%J Archive of "Nanomaterials".
%D 2017
%R 10.3390/nano7010017
%X Thick wafer-silicon is the dominant solar cell technology. It is of great interest to develop ultra-thin solar cells that can reduce materials usage, but still achieve acceptable performance and high solar absorption. Accordingly, we developed a highly absorbing ultra-thin crystalline Si based solar cell architecture using periodically patterned front and rear dielectric nanocone arrays which provide enhanced light trapping. The rear nanocones are embedded in a silver back reflector. In contrast to previous approaches, we utilize dielectric photonic crystals with a completely flat silicon absorber layer, providing expected high electronic quality and low carrier recombination. This architecture creates a dense mesh of wave-guided modes at near-infrared wavelengths in the absorber layer, generating enhanced absorption. For thin silicon (<2 ¦Ìm) and 750 nm pitch arrays, scattering matrix simulations predict enhancements exceeding 90%. Absorption approaches the Lambertian limit at small thicknesses (<10 ¦Ìm) and is slightly lower (by ~5%) at wafer-scale thicknesses. Parasitic losses are ~25% for ultra-thin (2 ¦Ìm) silicon and just 1%¨C2% for thicker (>100 ¦Ìm) cells. There is potential for 20 ¦Ìm thick cells to provide 30 mA/cm2 photo-current and >20% efficiency. This architecture has great promise for ultra-thin silicon solar panels with reduced material utilization and enhanced light-trapping
%K nano-photonics
%K solar cell
%K light-trapping
%K scattering
%U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5295207/