Ruthenium(II)-complex thin film, bearing pyridine-based tridentate was deposited on p-Si substrate by spin coating technique. The I-V measurements across the junction showed rectifying behavior. The reverse bias current of the heterojunction diode increased with increasing illumination intensity. The sensitivity to the light of I-V characteristics was attributed to the photocatalytic effect of Ruthenium(II)-complex. Ruthenium(II)complex thin film exhibited a transparency higher than 70% in the visible part of the spectrum. The band gap of Ruthenium(II)-complex film was calculated to be 4.42 eV. The reflectance data can be analyzed to determine optical constants such as refractive index and dielectric constant. The results indicate that Ruthenium(II)complex can be used in fabrication of high photosensitive diodes. (C) 2015 Elsevier Ltd. All rights reserved.