Thermostimulated transformations in nanosized Bi-MoO3 systems

Abstract

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 ([(Va)++e]) center during the preparation of a MoO3 film, the transformation of this center into a ([e(Va)++e]) center during the formation of Bi-MoO3 systems, and the thermal transition of an electron to the level of a ([(Va)++e]) center to form a ([e(Va)++e]) center.