This thesis focused on the study of dye-sensitized solar cells (DSSCs) based on ZnOrnnanoparticle. Our work started by synthesizing ZnO nanopartcile using sol-gel method.rnZnO nanoparticles were synthesized and the size of the nanoparticle (1.14 nm) was determinedrnby using effective mass approximation model.rnNatural sensitizers extracted from Jacaranda mimosifolia, Bougainvillea spectabilis,rnCarissa ovata, Amarathus iresine, Beta vulgaris, and Hibiscus sabdariffa used for sensitizingrnZnO nanoparticle. All natural sensitizers were extracted by water and ethanol,rnabsorption spectra were measured and all natural sensitizers absorbs in the visible region.rnDevices were fabricated using ZnO nanoparticles and with all the above natural sensitizers,rnthen the photoelectrochemical performance were measured. DSSCs based on ZnOrnnanoparticles and ethanol extract of Amarathus iresine sensitizers have shown relativelyrngood conversion efficiency of 0.039.rnThe incident photon to current conversion efficiency (IPCE), short circuit current densityrn(Jsc) and Voc were measured for all the above sensitizers. Also comparative study werernmade using TiO2 nanoparticle based DSSCs sensitized by Bougainvillea Spectabilis,rnCarissa ovata, and Jacaranda mimosifolia with ZnO based DSSCs sensitized by the samernsensitizers. In TiO2 nanopartcile based DSSCs the photoelectrochemical (PEC) performancernwe found relatively higher than the ZnO nanopartcles based DSSCs as expected.rnThe data we got from TiO2 and ZnO based DSSCs was analyzed and finally some of thernproblem that limit the conversion efficiency were discussed.