Multilayer structures based on matrices of CdSe and CdSe/ZnS nanoparticles in polyimide (PI) and poly[2-methoxy- 5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) were prepared and investigated. A comparison of photoluminescence of the various matrices excited by visible and ultraviolet laser radiation was carried out. The main contribution to the photoluminescence was made by the organic semiconductors. Quantum yield of the luminescence of CdSe nanoparticles embedded in organic semiconductor matrix was found to be lower then that of the individual CdSe nanoparticles dispersed onto a glass substrate. This difference was shown to be a result of charge transfer from the nanoparticles to organic molecules. The nanoparticles were responsible for photovoltage in thin layers of the PI/nanoparticles composites. Processing of a surface of electrodes and organic semiconductors by oxygen plasma increased the photovoltaic efficiency.