Overall, CdSe:Ag+ quantum dots were prepared by the successive ionic layer absorption and reaction method using two solutions: mixing molar concentrations of 0.003 mM AgNO3 and a Cd(CH3COO)2·2H2O anion to make solution 1 and 2.27 g Se powder and 0.6 M Na2SO3 were dissolved in 100 ml deionized water, solution 2. The FTO was coated with TiO2 nanoparticles and then was dipped in both solutions, which created a FTO/TiO2/CdSe:Ag+ photoanode with a thickness of 1 layer to 4 layers. The layers of the CdSe:Ag+ film show an effect on the morphology, crystalline structure, optical properties, and photovoltaic through optical and photovoltaic measurements. Finally, the performance of the device based on a FTO/TiO2/CdSe:Ag+ photoanode with the different thickness increased significantly to exactly 3.96%. Moreover, in the pattern of an explanation of the optical and photovoltaic properties of materials, we use Tauc’s theory to determine the band gap, the conduction band, and the valence band.