Optical and electrical properties of niobium-doped indium oxide thin films prepared by co-sputtering technique

Indium oxide (In₂O₃) based thin films have attracted much attention due to their high transparency and low resistivity. In order to obtain good transmittance and high conductivity, niobium (Nb) element was chosen as dopant in In₂O₃ in this study. Nb-doped In₂O₃ thin films (InNbO) were deposited on substrate by co-sputtering technique. The influence of Nb content on the structural, optical and electrical properties of InNbO thin films was systematically investigated. These thin films are compact and uniform without obvious pores and cracks. And InNbO is cubic bixbyite structure similar to In₂O₃. When Nb content is 1.8 at%, the resistivity of InNbO is as low as 8.29 × 10⁻³ Ω·cm. The prepared thin films exhibit high optical transmittance from visible to near-infrared wavelength regions. The average transmittance of InNbO thin films can reach 80.74 % in visible light range (380 ∼ 750 nm), and 75.71 % in near-infrared region (750 ∼ 2400 nm).