Preparation and characterization of chromium oxide thin films: The response of morphology, crystal structure, and electrical properties to oxygen pressure under magnetron sputtering.

This study focuses on Cr 2 O 3 prepared via reactive magnetron sputtering, a direct deposition technique that significantly impacts the microstructure and optoelectronic properties of the films. Reactive sputtering alters grain size, density, and surface morphology, which in turn affects the structural order and stoichiometry. By adjusting the ratio of process gases, particularly the oxygen partial pressure, the stoichiometry of the deposited films was controlled. This is crucial for managing the oxidation state of chromium and the concentration of free electrons. An optimal oxygen partial pressure of 75 % was identified, substantially reducing oxygen interstitial defects in the CrO x materials and enhancing conductivity by nearly two orders of magnitude. Additionally, increasing the oxygen partial pressure helped integrate more oxygen atoms into the lattice, transitioning the electronic structure from a metallic state in CrO 2 to a semiconductive state in CrO 3. This fine-tuning of oxygen doping not only adjusts carrier concentrations but also optimizes the photoelectric properties of the materials, achieving a tailored high band gap of 3.34 eV. This study highlights the potential of reactive magnetron sputtering to customize semiconductor materials through oxygen doping, offering a novel approach to enhance the versatility and application range of chromium oxide materials in advanced technological applications. • Versatile Synthesis: Enhances Cr 2 O 3 film properties via reactive magnetron sputtering. • Stoichiometry Control: Adjusts oxygen pressure to control chromium's oxidation state. • Increased Resistivity: Significantly increases resistivity by optimizing oxygen partial pressure. • Electrical Property Optimization: Tailors electrical properties with precise oxygen doping. [ABSTRACT FROM AUTHOR]