Investigation of structural and optical properties of ZnO thin films deposited on glass substrates by wet chemical sol-gel technique

Abstract

Nickel doped ZnO (NZO) and undoped ZnO thin films were deposited by wet chemical sol-gel spin coating method and their optical and structural properties have in detail been investigated by X-ray diffraction and optical absorption measurements to observe the effect of doping with different values of Ni molarity. The NZO and undoped ZnO thin films showed a growing trend along the c-axis perpendicular to the substrate surface. The strong (002) diffraction peaks at 2? = 35.743°, 35.836°, 35.840° and 36.041° were observed to belong to samples undoped ZnO, NZO (0.25%), NZO (0.50%) and NZO (0.75%) films, respectively. The band gap values have been calculated from the dependencies ($({a^ 2}$vs h?) byextrapolating the straight lines to $({a^ 2}$= 0 and found as 3.2630eV and 3.2820 eV for 0.75% NZO and undoped ZnO thin films, respectively.