Abstract Transparent nanocomposite films were spin-coated from sulfonic acid modified polycarbonate and fluorescent dye 3-(benzothiazol-2-yl)-7-(diethylamino)-2-oxo-2H-1-benzopyran-4-carbonitrile) and doped with different concentrations of ZrO 2 nanoparticles to form fluorescent PC/ZrO 2 nanocomposite films. The refractive index of the investigated nanocomposite films was increased by increasing the amount of ZrO 2 NPs. It was also found that, adding zirconia nanoparticles controlled the orientation of dye molecules in PC host leading to enhanced fluorescence anisotropy. The trapping efficiency was calculated as a function of dipole orientation for all concentrations of ZrO 2 NPs and reached 96.5% for vertically aligned dye molecules and 90.6% for horizontally aligned. These results indicated that aligning the transition dipoles of dye molecules is promising for the enhancement of the edge emission of luminescent solar concentrator (LSC) waveguides.