Structural, optical and electrical properties of spray deposited indium-doped Cr₂O₃ thin films

This research deals with the study that investigates the effects of indium-doped Cr2O3 thin films on the structural, morphological, optical and electrical properties with different concentrations of indium (0, 2, 4, 6 and 8 wt%). Indium-doped Cr2O3 thin films were elaborated on glass substrates using a homemade pneumatic spray pyrolysis instrument at a temperature of 500 degrees C. Structural studies showed that these films have a rhombohedral structure preferentially oriented along the (110) direction. The crystallite size was in the range of 23-57 nm. The SEM images revealed that the films were well-adherent and crack-free. The optical transmittance of films increased up to 94% for 4 wt% In-doped Cr2O3 films and then decreased at 6 and 8 wt%. The optical band gap values were determined 3.52, 3.60, 3.93, 3.49 and 3.46 eV at 0, 2, 4, 6 and 8 wt% of indium, respectively. The highest conductivity value of 79 (omega cm)(-1) and the best figure of merit value 1.2 x 10(-3)(omega(-1)) are obtained for the 4 wt. %In-doped Cr2O3 films.