Yb3+ doped phosphors with the wide photoluminescence band have attracted great attention recently due to their application in the ultra-short pulse laser pumped by laser diode. It was found that the full width at half maximum (FWHM) of photoluminescence of Yb3+:Gd2GeMoO8 is up to 72 nm, which is desirable for the ultra-short pulse laser. Single crystals of (4.94 wt%)Yb3+-doped Gd2GeMoO8 were grown by the flux method from MoO3 self-flux. Transparent Yb3+:Gd2GeMoO8 single crystals with dimension up to 4 x 3 x 3 mm(3) were grown successfully. The crystal structures of Gd2GeMoO8 and Yb3+:Gd2GeMoO8 were determined by Rietveld refinement to X-ray powder diffraction patterns, and their atom coordinates were obtained. The absorption and emission spectra of Yb3+:Gd2GeMoO8 were measured at room temperature, their crystal field energy transitions were assigned. The fluorescence decay time of 1013 nm is determined to be 201.9 and 35.0 mu s. Work indicates that Yb3+:Gd2GeMoO8 is a potential laser material used in the ultra-short pulse and tunable all-solid-sate laser. (C) 2010 Elsevier B.V. All rights reserved.