Effect of substrate temperature on opto-electrical properties of Nb-doped In2O3 thin films

R. K. Gupta, Missouri State University
K. Ghosh, Missouri State University
P. K. Kahol, Missouri State University


Highly conducting and transparent Nb-doped In2O3 thin films were deposited on quartz substrate using pulsed laser deposition technique. The effect of substrate temperature on structural, electrical and optical properties was studied. The XRD results show that the films grown at low temperature are amorphous, while the films grown at higher temperature are crystalline. Atomic force microscopy (AFM) shows that films are very smooth with root mean square roughness of 2.1 nm. The conductivity and mobility of the films increase with increase in the substrate temperature. The resistivity and mobility of the films grown at 600 °C are 9.16×10-5 Ω cm and 85 cm2/V s, respectively. The transparency of the films is seen to largely depend on the growth temperature. The transparency and band gap are found varying between 62-84% and 3.52-3.82 eV, respectively, for various temperatures.