Effect of GLAD technique on optical properties of ZnS multilayer antireflection coatings

Highlights: • ZnS multi-layer antireflection coatings have been prepared by GLAD technique. • XRD analysis depicts that all the multi-layer samples are crystallized in cubic structure. • FESEM images confirmed the multi-layer and inclined formation of specimens. • Transmission increment and refractive index decrement obtained for the multi-layer samples. • Incredible impression of GLAD technique on multi-layer coatings is realized. - Abstract: In this work, we prepared Zinc sulfide (ZnS) multi-layer antireflection coatings applying glancing angle deposition (GLAD) technique by physical vapor deposition method. By comparing the structural and optical properties of the samples prepared at normal and inclined single layer coatings, salient effect of multi-layer coatings composed of normal and inclined layers are observed. Relative improvement in crystallinity of the GLAD produced films with respect to inclined single layer resulted from X-ray diffraction (XRD) studies. Despite high increment in average transmission, explicit reduction in refractive index of the multilayer specimens are obtained by Ultraviolet–visible spectroscopy (UV–VIS) analysis. Both the abovementioned changes are in the direction of improving the anti-reflectivity features.