Theoretical analysis of the 2,5-diphenyloxazole dye molecule and newly designed dyes were performed using Density Functional Theory. The ground state and excited state oxidation potential as well as electron injection from dyes to TiO2 are reported. Improved light harvesting efficiency and free energy change of electron injection of newly designed sensitizers reveal that these materials would be excellent sensitizers. This theoretical designing will pave way for the experimental list to synthesis the efficient sensitizers for solar cells. The study of structural, electronic and optical properties for these compounds could help to design more efficient functional photovoltaic organic materials.