Enhanced performance by incorporation of zinc oxide nanowire array for organic-inorganic hybrid solar cells

We study the solar power conversion efficiency in hybrid solar cells based on zinc oxide (ZnO)/antimony trisulfide (Sb2S3)/poly-3(hexylthiophene) heterojunctions. The incorporation of ZnO nanowire arrays (NAs) structure results in power conversion efficiency of 2.9%, or 20% higher than the control device. Absorption spectra and numerical simulation analysis provide strong evidence revealing that the enhanced performance is mainly induced by (1) enhanced optical absorption from light-trapping effect of NAs and (2) reduced bulk recombination rate in Sb2S3 from shortened electron injection pathway into ZnO. Significantly, numerical simulations show that the expected interface recombination increase from larger interfacial area effects is negligible. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4728985]