Smart multifunctional V ₂ O ₅ is an appealing oxide for energy-saving and energy-storage applications.

The temperature dependence of the interband transition in an α-V₂O₅ film was investigated using absorption and photoluminescence spectral measurements at a temperature range of 10–300 K. Transmission measurements in the experimental temperature range indicate that the α-V₂O₅ film has two distinct interband transitions, implying indirect and direct transitions. This result was confirmed by spectroscopic ellipsometry. The blue shift of both the transitions in the α-V₂O₅ film with decreasing temperature was explained by a reduction in the lattice-dilatation effect and the electron-phonon interaction. The PL measurements in the experimental temperature range showed that the emission near 530 nm is due to the indirect transition in the α-V₂O₅ film.