The dinuclear copper(I) complex bearing a diphosphine dioxide (dppaO(2)(-) = bis(diphenylphosphino) amide dioxide) ligand and dppm (= bis(diphenylphosphino) methane) ligands was synthesized and the photophysical properties were examined. This complex shows strong light blue emission in the solid state. The photophysical properties of the complex are discussed with the result of DFT and TD-DFT calculations.