Urchin-inspired zinc oxide as building blocks for nanostructured solar cells

High surface area nanowire based architectures have been identified as important components for future optoelectronic nanodevices, solar cells, wettability coatings, gas sensors, and biofuel cells. Here we report a novel urchin-inspired nanowire architecture: its interwoven threedimensional, high-surface-area nanowire arrangement can be precisely controlled by using a combination of nanosphere lithography, low-temperature atomic layer deposition, and electrodeposition. The performance of monolayer arrays of urchin-inspired ZnO nanowire building blocks competes to that of planar nanowire carpets. We illustrate this capability by fabricating fully-inorganic extremely thin absorber solar cells using CdSe as absorber layer and CuSCN as hole-collector material. The light diffusion of the urchin-inspired nanowire arrays was varied from 15% to 35%. Homogenous absorption in the wavelength range 400-800 nm of up to 90% was obtained. Solar conversion efficiencies of similar to 1.33% were achieved. (C) 2012 Elsevier Ltd. All rights reserved.