Sol-Gel Synthesis of Zinc oxide Semiconductor Powder for Varistor Structures

Abstract

Synthesis of ZnO powders created by the sol-gel method for the use in the production of varistors is currently one of the promising areas. This method allows mixing of additives at the atomic level, which promotes a homogeneous distribution of impurities, it also makes it possible to control the particle size, which contributes to the miniaturization of the varistor and does not require secondary heating, and is also an environmentally friendly method. In this work, we carry out the synthesis of ZnO varistor powder with further fabrication of the varistor structure within the framework of the sol-gel method, as well as the study of the obtained samples at all stages of work. During the synthesis process, the ZnO powder was obtained by the sol-gel method, from which samples of varistor structures were made, at a sintering temperature of 900 °C. During the synthesis, the sol was studied at all stages of maturation by IR-Fourier spectroscopy; during the study, the formation of nano-aggregates in the gel and the presence of ZnO in the resulting powder were obtained. The structure of the instrumental samples was studied by scanning electron microscopy, during which the average grain size of ZnO was calculated as 0.25μm. The constructed volt-ampere characteristics in the voltage range of —220...220 Vhad a distinct non-linearity with a coefficient of 2.36.