Effect of thickness on structural, optical and mechanical properties of Mn doped ZnO nanocrystalline thin films RF sputtered in nitrogen gas environment

Thin films of Zn0.95Mn0.05O were synthesized by RF- sputtering in nitrogen gas environment. Structural, optical and mechanical properties of the films with thickness ranging from 398 to 1650 nm are studied. The X-ray diffraction (XRD) results show that the as-deposited films are oriented along the (002) direction with hexagonal wurtzite structure. The field emission scanning electron microscopy (FESEM) studies show an increase in grain size with increase in thickness. Optical transmission studies show band gap values in the range 3.03-3.37 eV. The values of hardness and Young's modulus are found to be in the range 14-18 GPa and 122-167 GPa at an indentation depth of 100 nm respectively. The role of nitrogen doping on the microstructure and properties of films is discussed. (C) 2014 Elsevier Ltd. All rights reserved.