A novel 1-D chain complex {[Ni(azobenzene-4,4′-dicarboxylic acid)(ethylenediamine)2](N,N-dimethylformamide)2}(named as Ni1) was designed, synthesized, characterized, and demonstrated as an efficient sensitizer for dye-sensitized solar cells. The structure of Ni1 was characterized by single-crystal X-ray diffraction, infrared (IR) spectra, and elemental analysis. The optical, electrochemical and photovoltaic properties of Ni1 were investigated by UV–visible spectroscopy, cyclic voltammetry, and the photocurrent-photovoltage measurement. The results show that the incident photo-to-current conversion efficiency of cells based on Ni1 was obviously improved in blue light region of solar spectra. The overall conversion efficiency of the dye-sensitized solar cells using Ni1 was increased by 62% under AM 1.5 illumination (100mWcm−2).