In order to demonstrate efficiency improvement of solar cells through utilization of frequency-shifted sub-band-gap photons, we prepared Y(3)Al(5)O(12) transparent ceramics co-doped with 3.0 at% Yb(3+) and 0.5 at% Er(3+) (YAG:3.0Yb/0.5Er) by solid state reaction. The material's upconversion luminescence was investigated and it was found that near-infrared light could be effectively converted to green light centered at 563 nm, where a dye-sensitized solar cell normally possessed high spectral response. Using a thin disk of YAG:3.0Yb/0.5Er transparent ceramics attached to the rear of the dye-sensitized solar cell, the near-infrared response of the dye-sensitized solar cell was enhanced, due to the frequency upconversion. (C) 2010 Elsevier B.V. All rights reserved.