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

Monoclinic VO 2 , a semiconductor with a narrow bandgap, is highly suitable for infrared (IR) spectrum utilization. The electrical and optical properties of VO 2 doped with X are thoroughly examined. Specifically, Mg doping decreases the formation of V–V dimers. The presence of the 3 d orbitals of the V atoms and the 2 s orbital of the Mg atom leads to a decrease in the bandgap. This leads to an absorption peak of 10 4 in the mid‐infrared (mid‐IR) range, resulting in an optical absorption that is approximately ten times greater than that of pure VO 2 . As a result, it becomes simpler to detect. Notably, the responsiveness of the system doped with Mg to IR light increases. VO 2 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 VO 2 in IR technology.