Preparation and characterization of Al_2xIn_2−2xO₃ films deposited on MgO (1 0 0) by MOCVD

Highlights: • Ternary Al_2xIn_2−2xO₃ alloy films were deposited on MgO (1 0 0) by MOCVD. • The microstructure of the Al_2xIn_2−2xO₃ films were studied upon HRTEM. • Al_2xIn_2−2xO₃ alloy films exhibited great optical transparency in the visible wavelength range. • The band gap of the Al_2xIn_2−2xO₃ films can be modulated by controlling the Al contents in the samples. - Abstract: The ternary Al_2xIn_2−2xO₃ films with different compositions x[Al/(Al + In) atomic ratio] have been fabricated on the MgO (1 0 0) substrates by the metal organic chemical vapor deposition (MOCVD) method. The influence of different Al contents on the structural, optical and electrical properties of Al_2xIn_2−2xO₃ films has been studied. The structural studies reveal a change from single crystalline structure of cubic In₂O₃ to amorphous as the Al content increases. The average transmittances of all samples in the visible range are over 80%. The optical band gap is observed to increase monotonically from 3.67 to 5.38 eV as the Al content increases from 0.1 to 0.9