Nitrogen-doped carbon nanodots synthesized from L-arginine and ethylenediamine (NCNDs); citric acidderived carbon nanodots with carboxylic surface groups (α-CDs); and Silica-Cdots hybrids produced through coupling α-CDs to SiO 2 nanoparticles were used for the fabrication of uorescent PMMA-CDs optical lms. PMMA naturally emits luminescence when irradiated by 300-320 nm and the nanoparticles occlusion allows the conversion of a broader UV bandwidth to the visible: emissions around 450 nm are observed for excitations from 330-360 nm. Since this photoluminescence could increase the e ciency of solar energy concentrators and generators, photovoltaic cells were coated with lms obtained with the blue-emitting NCNDs for a proof-of-concept of increasing the cells' e ciencies with such materials. At our preliminary experiments, even using a setup with low contact of the optical polymer lm on silicon surface, a promising increase from 4.24% to 4.72% cell e ciency was observed, showing the feasibility and potential for application of these environmentally friendly materials.