Tunable metal-insulator transition in strained V2O3 thin films epitaxially grown on SiC substrates

V2O3, as a typical strongly correlated material, possesses great application value due to its unique metalinsulator transition property. However, the difficulty of epitaxially growing high-quality V2O3 thin films on semiconductor substrates has dramatically limited its development in electronic devices. Here, we utilize the similarity of the local structure of the (001) plane to achieve the epitaxial growth of high-quality V2O3 thin films on the 4H-SiC substrate. By changing the strain in the films to induce the paramagnetic metal (PM) to paramagnetic insulator (PI) transition occurrence, we realize a giant resistivity change (AR/R = 107 500%) at room temperature. Raman spectra results show that the electrical properties of the strain-controlled films are realized by increasing/decreasing the a1g orbital occupation, supporting the scenario of trigonal distortion, in which the PM-PI transition can be understood as orbital-selective MIT caused by small changes in the trigonal distortion. The ability to epitaxially grow on semiconductor substrates and to modulate electrical properties by strain makes V2O3/4H-SiC thin films an ideal platform for exploring and studying Mott devices.