Thermal transformations in nanosized MoO3 layers

The degree of the transformation of MoO₃ films (d= 8–130 nm) increased as the duration (1–140 min) and temperature (373–573 K) of thermal treatment grew and as the film thickness decreased under atmospheric conditions. The thermal treatment of MoO₃ films decreased the optical density at λ = 350 nm and caused the appearance of an absorption maximum at λ = 870 nm. A mechanism of thermal transformations of MoO₃ was suggested. The mechanism included the formation of the [(V _a)⁺⁺e] center during the preparation and thermal treatment of MoO₃ films and thermal electron transition from the valence band to the [(V _a)⁺⁺e] center level with the formation of the [e(V_a)⁺⁺e] center.