LAUSR

Abstract The present work demonstrates the synthesis of MgO and ZnO–MgO nanospheres with various concentration (2, 4, 6, 8 and 10 wt%) of Zn2+ through microwave combustion route using magnesium nitrate and zinc nitrate as precursors and ethylene glycol as solvent. The effect of doping was studied through powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive analysis using X-rays (EDAX), transmission electron microscopy (TEM) and photoconductivity (I–V) technique. Tryptan Blue, SPADNS and Evans Blue dyes were used for the first time as a photosensitizer on ZnO–MgO nanoparticles. Optical and electrochemical characteristics of dyes revealed that the optical bandgap, HOMO and LUMO levels of dyes are well matched with conduction band of ZnO–MgO nanoparticles. I–V characteristics of ZnO–MgO films before and after sensitisation with dyes revealed the influence of dye sensitisation on photo conductivity of ZnO–MgO nanoparticles. In addition, the better adsorption of Trypan Blue (TB), SPADNS (SPD) and Evans Blue (EB) dyes on ZnO–MgO film is due to porous nature of ZnO–MgO. This gives more transportation of electron from dye to ZnO–MgO which enhances the power conversion efficiency of solar cell.