Aim of this work is to develop Luminescent Solar Concentrator (LSC) matrix material suitable to absorb NIR and visible part of solar spectrum and emit light within Si absorption range. The synthesis of transparent material by the incorporation of clusters of Nd:Yb:YAG; Nd:Yb:GGG and Nd:Yb:Y2O3 nanocrystals into polymethyl mathacrylate (PMMA) polymer matrix and their subsequent characterization are presented. The redispersion of nanocrystals was done by ultrasonification directly in methyl methacrylate monomer (MMA). The influence of surface active agents has been analyzed in selected samples. Agglomerate sizes after redispersion process were in the range of 10 nm to 100nm. The good optical quality samples has been obtained by using UV polymerization process. Strong fluorescence signal from Yb3+ ions with main peak centered at 1026 nm was observed by direct excitation of Yb3+ ions at 970 nm as well as by excitation of Nd3+ ions at 808 nm. Spectral characteristics are presented and discussed. The results indicate that investigated polymer materials with rare earth contained oxide nanocrystals can be used for NIR conversion for silicon PV application.