摘要：Hydrogenated amorphous Si （a-Si：H） is a promising material f.r photovoltaic applications due to its low cost, high abundance, long lif.time, and non-toxicity. We demonstrate a device designed to investigate the ef.ect of.nanostructured back ref.ectors on quantum ef.iciency in photovoltaic devices. We adopt a superstrate conf.guration so that we may use conventional industrial light trapping strategies f.r thin f.lm solar cells as a ref.rence f.r comparison. We controlled the nanostructure parameters via a waf.r-scale self.assembly technique and systematically studied the relation between nanostructure size and photocurrent generation. The gain/loss transition at short wavelengths showed red-shif.s with decreasing nanostructure scale. In the inf.ared region the nanostructured back ref.ector shows large photocurrent enhancement with a modif.ed f.ature scale. This device geometry is a usef.l archetype f.r investigating absorption enhancement by nanostructures.