Modulation of the Electronic Structure and Optical Properties of VO2 by Doping with X (X = Be, Mg, Al, Ga)

Monoclinic VO2, a semiconductor with a narrow bandgap, is highly suitable for infrared (IR) spectrum utilization. The electrical and optical properties of VO2 doped with X are thoroughly examined. Specifically, Mg doping decreases the formation of V–V dimers. The presence of the 3d orbitals of the V atoms and the 2s orbital of the Mg atom leads to a decrease in the bandgap. This leads to an absorption peak of 104 in the mid‐infrared (mid‐IR) range, resulting in an optical absorption that is approximately ten times greater than that of pure VO2. As a result, it becomes simpler to detect. Notably, the responsiveness of the system doped with Mg to IR light increases. VO2 significantly increases the photocurrent density, with a 1000‐fold increase in the mid‐IR region and a tenfold increase in the near‐IR region. This finding provides a theoretical basis for empirically exploring VO2 in IR technology.