Engineering of Ultraviolet reflectors by varying alternate layers of Titania/Silica for harmful UV-protection.

This paper presents the engineering of ultraviolet (UV) reflectors made up of alternate layers of titania (TiO2) and silica (SiO2) by using the sol-gel spin coating method. The choice of these two materials is appropriate to realize the optical reflectors due to their large refractive index contrast. The formation of multilayer films of TiO2 and SiO2 are studied by field emission scanning electron microscopy (FESEM), while UV-vis spectroscopy measurement is performed to study the reflectance. By varying the number of TiO2/SiO2 stacks, we have achieved the maximum reflectance within the UV region at center wavelengths of 335 nm, 358 nm, and 367 nm corresponding to the 3-, 6-, and 9-stacks based reflectors. Finally, it is summarized that these reflectors prohibit the propagation of ultraviolet light, and therefore, promising for UV protection coating. [ABSTRACT FROM AUTHOR]