Luminescent Cu(Ⅰ) complexes have witnessed impressive developments due to their interesting photo-physical properties including room temperature phosphorescence(RTP) and thermally activated delayed fluorescence(TADF).[1,2] This case study on dinuclear copper(Ⅰ) complexes with N^P ligand(diphenylphosphine-substituted phenylbenzimidazole derivatives)provides a deeper insight into the effect of substitution on luminescence mechanisms and a reference for designing efficient Cu(Ⅰ) iodide emitters.