Effect of post-deposition annealing on the structural, optical and electrical properties of ZTO/Ag/ZTO tri-layered films

Abstract

Sn-doped ZnO (ZTO)/Ag/ZTO trilayer films were deposited on glass substrates by radio frequency (RF) and direct current (DC) magnetron sputtering with ZTO and Ag targets, respectively. The films were annealed at 100, 200 and 300°C for 30min to investigate the effects of annealing temperature on their structural, electrical, and optical properties. The thicknesses of the ZTO and Ag interlayer were kept constant at 50 and 15nm, respectively, by controlling the deposition time. Although all films show a (111) diffraction peak of Ag in the XRD patterns irrespective of the annealing temperature, the films annealed at 300°C show a larger grain size of Ag interlayer than the other films. As annealing temperature increases, the optical transmittance in the visible wavelength region also increases from 83.2% to 84.0%, and electrical resistivity decreases to as low as 7.48×10−5Ωcm at an annealing temperature of 300°C. The figure of merit reveals that ZTO/Ag/ZTO films annealed at 300°C have higher optical and electrical performance than the other films prepared under different conditions.