@article{Hsu2011, author = {Chingmei Hsu and George F. Burkhard and Michael D. McGehee and Yi Cui}, title = {Effects of Nanostructured Back Reflectors on the External Quantum Efficiency in Thin Film Solar Cells}, year = {2011}, journal = {Nano Research}, volume = {4}, number = {2}, pages = {153-158}, keywords = {scattering, Solar cells, solar energy, amorphous silicon, back reflector}, url = {https://www.sciopen.com/article/10.1007/s12274-010-0064-y}, doi = {10.1007/s12274-010-0064-y}, abstract = {Hydrogenated amorphous Si (α-Si: H) is a promising material for photovoltaic applications due to its low cost, high abundance, long lifetime, and non-toxicity. We demonstrate a device designed to investigate the effect of nanostructured back reflectors on quantum efficiency in photovoltaic devices. We adopt a superstrate configuration so that we may use conventional industrial light trapping strategies for thin film solar cells as a reference for comparison. We controlled the nanostructure parameters via a wafer-scale self-assembly technique and systematically studied the relation between nanostructure size and photocurrent generation. The gain/loss transition at short wavelengths showed red-shifts with decreasing nanostructure scale. In the infrared region the nanostructured back reflector shows large photocurrent enhancement with a modified feature scale. This device geometry is a useful archetype for investigating absorption enhancement by nanostructures.} }