Dependence of the Conductivity Mechanism and Dielectric Properties of Zinc Oxide Films on the Degree of Lithium Doping

The effect of lithium impurity on the dielectric characteristics and the mechanism of conductivity of zinc oxide thin films obtained by the electron beam deposition method was studied. At low frequencies, a strong dispersion of permittivity constants associated with interfacial polarization at grain boundaries was found. It was shown that the frequency dependencies of the conductivity are well described by the Mott theory. It has been established that the mechanism of ac conductivity undergoes qualitative changes with increasing lithium concentration: hopping conductivity is replaced by correlated hops through the barrier and tunneling of small radius polarons. The characteristics of the obtained films indicate the possibility of using them to create a capacitive memory element and a channel of a field-effect transistor.