Polycarbonate (PC) is considered as an amorphous, robust, thermoplastic polymer with remarkable optical properties due to repetition of linear polyester of carbonic acid and dihydric phenol monomer in a free chain configuration, which confer rigidity to the structure.1 The daily infringement of common solar light spectra within this thin polymer assembly, with transparency in the visible solar spectrum (value up to 70%), can be observed for window or roofs and many other applications. However, PC remains a soft material vulnerable to the effects of damage versus solar radiation and the introduction of nanoparticles may represent a valid solution to increase the shield to the u.v range and to retard effect of fragmentation and colour changes. Among metal nanoparticles, few lanthanide particles have properties to stabilize and screener this soft material from photo-initiated degradation.2 Cerium oxide nanoparticles offer this quality and employ to reduce the effect of damage with an appropriate shield in the UV range and is currently used also as component for screen filter in catalyst or to smooth scratches from glass surface.3 In more detail, the property to shield polycarbonate from UV radiation of solar spectra derive from electronic configuration of cerium with 4f level, which permit the transition to the 5d configuration of one active electron, which is generally a vacuum UV transition.4