Structural and Electrical Resistivity Study of Synthesized ZnO Thick Film Resistors

Abstract

ZnO nano powder was derived from Zinc nitrate and Dextrose by using self-propagating solution combustion technique precipitation method. The nano powder of ZnO was mixed with organic vehicle (OV) consists of butyl carbitol acetate and ethyl cellulose to form a paste. The paste was screen printed on alumina substrates using nylon screen of size 355 mesh. The white thick films were fired at temperatures of 500^oC, 600^oC and 700^oC for 2h. The fired films were analyzed using an X-ray diffractometer (XRD) to know its crystal structure and a Scanning Electron Microscope (SEM) to know its surface morphology. Electrical resistance of the thick films was measured at various temperatures in air. The electrical resistance of the thick films decreased with increase in temperature. The purpose is to understand the effects of firing temperature on resistivity, activation energy and TCR of the thick film resistors (TFRs). It is shown that the electrical properties are found to be functions of the temperature, non-stoichiometry and grain size of the ZnO material.