The structure of Hf(IV)porphyrins and Zr(IV)porphryins with polyoxometalates (POM) occupying the remaining coordination sites serve as models for binding these porphyrins to defect sites on oxide surfaces. Thus, Hf(IV)-tetraphenylporphyrin di-acetate, Hf(TPP)OAc₂, and Zr(IV)-tetraphenylporphyrin di-acetate, Zr(TPP)OAc₂, have potential applications for the sensitization of oxide band gap materials for solar cell devices. The hypothesis is that dyes such as porphyrins that complex oxophilic metals will bind better to the oxide surface via the ligated metal ion upon displacing OAc ligands, and this mode of binding will improve the efficiency of electron injection from the excited state dye to the conduction band of semiconductor. The deposition and optical characterization of these metalloporphyrins on ITO surfaces and TiO₂ nanoparticles will be discussed in comparison to the absorption and emission spectra of the metalloporphyrin in solution.