Structural, Optical, Electric and Magnetic Characteristics of (In1−xGdx)2O3 Films for Optoelectronics

Abstract

After (In1−xGdx)2O3 powder with a wide x range of 0 to 10 at.% was chemically produced, (In1−xGdx)2O3 thin films were evaporated under ultra-vacuum using an electron beam apparatus. We investigated the influence of the Gd doping concentration on the magnetic, optical, electrical, and structural properties of the resultant In2O3 deposits. The produced Gd-doped In2O3 films have a cubic In2O3 structure without a secondary phase, as shown by the X-ray diffraction results. Additionally, the chemical analysis revealed that the films are nearly stoichiometric. A three-layer model reproduced the spectroscopic ellipsometer readings to determine the optical parameters and energy gap. The Egopt changed toward the lower wavelength with growing the Gd doping in (In1−xGdx)2O3 films. The Egopt in the (In1−xGdx)2O3 films was observed to increase from 3.22 to 3.45 eV when the Gd concentration climbed. Both carrier concentration and hall mobility were found during the Hall effect studies. It was possible to construct the heterojunction of Ni (Al)/n-(In1−xGdx)2O3/p-Si/Al. At voltages between −2 and 2 volts, investigations into the dark (cutting-edge-voltage) characteristics of the produced heterojunctions were made. The oxygen vacancies and cationic defects in the lattice caused by the uncompensated cationic charges resulted in significant magnetism and ferromagnetic behavior in the undoped In2O3 films. The (In1−xGdx)2O3 films, however, displayed faint ferromagnetism. The ferromagnetism seen in the (In1−xGdx)2O3 films was caused by oxygen vacancies formed during the vacuum film production process. Metal cations created ferromagnetic exchange interactions by snatching free electrons in oxygen.