Thermostimulated transformations in nanosized Bi-MoO3 systems

Transformations in Bi-MoO₃ nanosized systems are studied by optical spectroscopy, microscopy, and gravimetry. The contact potential difference for the Bi and MoO₃ films and the photovoltage of the Bi-MoO₃ systems are measured, depending on the thickness of Bi (d = 3–92 nm) and MoO₃ films (d = 5–40 nm) and the temperature (373–673 K) and time of heat treatment. An energy band diagram of the Bi-MoO₃ systems is constructed. A model of the thermal transformation of MoO₃ films in Bi-MoO₃ systems is proposed that involves the redistribution of equilibrium charge carriers on a contact, the formation of a ([(V_a)⁺⁺e]) center during the preparation of a MoO₃ film, the transformation of this center into a ([e(V_a)⁺⁺e]) center during the formation of Bi-MoO₃ systems, and the thermal transition of an electron to the level of a ([(V_a)⁺⁺e]) center to form a ([e(V_a)⁺⁺e]) center.