Effects of nanostructured back reflectors on the external quantum efficiency in thin film solar cells
Solar cells, back reflector, scattering, solar energy, amorphous silicon
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.
Tsinghua University Press
Chingmei Hsu,George F. Burkhard,Michael D. McGehee,Yi Cui, Effects of nanostructured back reflectors on the external quantum efficiency in thin film solar cells. NanoRes.2011, 4(2): 153–158