OPTICAL AND ELECTRICAL PROPERTIES OF HIGHLY [222] TEXTURED ITO ON GLASS

Abstract

Thin ITO films on glass having single crystalline direction [222] were deposited by magnetron dc sputtering. The high-texture ITO films [222] were obtained by using thin ITO buffers that were sputtered in oxygen-rich O+Ar mixture at early stage. X-ray patterns showed that ITO films had single direction [222] with film thickness up to 750nm. The resistivity, electron density and mobolity of ITO/buffer/glass films were 1.2 x 10^-4 W.cm, 10²¹ cm^-3 and 50 cm²V^‑1s^-1, respectively. The average transmittance in visible region (400-700nm) was 80%. The optical properties of the films were determined by using (extended Drude + Lorentz) dielectric function as a base to model the measured transmission spectra. The calculated refraction index at 0.55 mm was 1.8 and band gap was 4.3 eV. Furthermore, the value of the electron effective mass in conduction band was also deduced and had value in the range of 0.33m_e – 0.35m_e.