Abstract In this research, we evaluated the properties of ZrO₂ films produced with the glancing angle deposition technique and evaluated its effect on the detector properties. With using ZrO₂, we created films with a refraction index in the range of 1.3 to 2.0, and produced a four layer graded-index (GRIN) antireflection coating. A BGO scintillator sample with an applied GRIN coating demonstrated up to ∼ 53% light output enhancement in comparison with the reference ones. For LYSO scintillators, the observed magnitude of the effect was less, ∼ 11%. Thus, this method is a technologically applicable way to improve the characteristics of existing and projected detector systems.