Abstract
Studies concerned with the design of new inorganic materials for gas sensors based on semiconductor structures are analysed. The influence of adsorbed molecules on the electronic state and electrical conductivity of the surface and inner interfaces in semiconductor materials is discussed. The mechanism of gas sensitivity is considered taking metal/insulator/semiconductor, semiconductor/insulator/semiconductor, metal/semiconductor, and semiconductor/semiconductor structures as examples. Specific features of the behaviour of heterostructures based on nanocrystalline metal oxides on single-crystalline silicon substrates with a SiO2 dielectric layer are pointed out. The sensor properties of semiconductor structures in the detection of various molecules are described.