The present study reports on the performance of organic nitrogenous compound namely, benzotriazole (BTZ) in polyethylene oxide (PEO)-poly(methylmethacrylate) matrix in conjunction with potassium iodide and iodine as a blended polymer electrolyte and its application in TiO2 nanocrystalline solar cells. On comparison of electrical conductivity between five different compositions of benzotriazole, polymer matrix with 0.005 M of benzotriazole exhibited the best ionic conductivity with 1×10-5 Scm-1. The photochemical properties of the best conducting sample showed an open circuit voltage (Voc) of 7.4 V, short circuit current density (Jsc) of 6.74 mA, fill factor of 0.73 and efficiency (η) of 3.6%. The structural modifications in these doped polymer electrolyte were analysed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The complex impedance and dielectric analyses were carried out to completely understand the relevent ion conduction mechanism.