Uniform silver quantum dots decorated TiO 2 nanotubes (Ag-TiO 2 NTs) were synthesized via a simple reduction reaction in ethanol solvent. The size distribution of composite NTs arranges from 3 to 5 nm for Ag quantum dots and about 10 nm for TiO 2 NTs in diameter. The composite Ag-TiO 2 nanoparticles were incorporated in organic hybrid solar cells through doping into the active layer. Both the optical and electrical properties of the solar cells were improved. The photocurrent and fill factor of the devices were obviously increased after the Ag-TiO 2 NTs were introduced, accompanied with a greatly reduced series resistance as well as enlarged shunt resistance. Suppressed recombination due to efficient charge transfer from plasmonic Ag quantum dots to the attached TiO 2 NTs made contribution to the charge collection and transportation so that the fill factor was increased. Meanwhile, the enhanced light absorption resulted from effective incident light scattering by the Ag-TiO 2 NTs composite played a role in increasing photocurrent. As a result, solar cells with Ag-TiO 2 NTs generated an enhanced conversion efficiency up to 20 and 50 % compared to that adopting TiO 2 NTs and that without doping, respectively.