Green-emitting CsPbBr3 perovskite nanocrystals were synthesized by the modified hot-injection method using three different solvents. The produced nanocrystals showed a narrow green emission band centered at 515-520 nm with full width at half-maximum (FWHM) values of approximately 18-20 nm. The highest photoluminescence quantum yield (PLQY) was obtained for the nanocrystal sample synthesized using a paraffin liquid solvent, with a value of 70.1% under excitation at 450 nm. The CsPbBr3 nanocrystals film light-emitting diodes (LED) chip module showed a luminous efficacy of 40.7lm/Wrad. The white LED (WLED) with green CsPbBr3 and red CsPbI3 nanocrystal films emitted bluish-white light with a high color rendering index of 89, and the luminous efficacy of the WLED reached 16.3lm/Wrad.