Nanoparticles of cadmium peroxide (CdO 2 ) were immobilized in poly 2,2 bithiophene (PBTh) to build photoactive inorganic/organic interfaces (I/O/I). Studies indicated that the CdO 2 initially immobilized in the organic polymer partially decomposed to a low band gap CdO. Therefore we refer to this mixture as CdO 2 /CdO. The CdO 2 /CdO/PBTh assemblies were subjected to optical and photoelectrochemical investigations in aqueous electrolytes containing acetate, nitrate, or phosphate. The equilibrium mixture of CdO 2 /CdO influenced the optical conductivity and dielectric contents of the assemblies. Furthermore, O 2 played an important role in the charge separation and transfer processes. The effects of an applied magnetic field were investigated and reported. The results were explained on the basis of formation of hybrid sub-bands due to band alignments between the assembly components. The photo-induced charge generation of PBTh was improved by occlusion of CdO 2 in the polymer as was evident by the greater photocurrent generated by CdO 2 /CdO/PBTh than that generated by PBTh.