Band anisotropy and effective mass renormalization in strained metallic VO2 (101) thin films

Abstract

We explore how strain impacts the band structure of metallic-phase VO2 thin films deposited on TiO2(101) substrates. Employing a combination of X-ray absorption linear dichroism and valence band measurements, we demonstrate that strain can alter the intrinsic band structure anisotropy of metallic VO2. Our findings reveal that reducing the thickness of VO2 films leads to a more isotropic band structure. This observation is further supported by an analysis of the electronic population redistribution in the $${d}_{{||}}{-}{\pi }^{* }$$ bands, which affects the screening length and induces effective mass renormalization. Overall, our results underscore the potential of strain manipulation in tailoring the electronic structure uniformity of thin films, thereby expanding the scope for engineering VO2 functionalities. In this article we studied the evolution of band anisotropy in strained VO2(101) thin films. We found out that strain works as a control agent for the anisotropy and thus controls the features of VO2 bands structure. For this crystal orientation a large strain corresponds to a more homogeneous electronic structure of VO2. This impacts the electrons population redistribution between d|| and π bands, the screening length and the effective mass. By controlling the anisotropy and the band structure properties our results can ease the integration of VO2 into complex electronics.