Temperature Sensors based on Semiconducting Oxides: An Overview
  Earlier studies show that organic and inorganic semiconducting materials are the most promising materials for use in temperature sensors. In this brief review, attention will be focused on temperature sensors and its applications in various fields. In addition, we have investigated the temperature sensing characteristics of nanostructured ZnO and ZnO-CuO nanocomposite. For this purpose, ZnO and ZnO-CuO nanocomposite were synthesized via chemical precipitation method. Scanning electron microscopy and X-ray diffraction of sensing materials have also performed. The average crystallite size was 45 and 68 nm for ZnO and ZnO-CuO respectively. The pelletization of the synthesized powder was done using hydraulic pressing machine (MB Instrument, Delhi) under a pressure of 616 MPa at room ambient. This pellet was put within the Ag-Pellet-Ag electrode configuration for temperature sensing. Temperature sensitivities of above semiconducting oxides were calculated. Electrical properties of the materials establish the semiconducting nature of these sensing pellets. In addition, the activation energies of ZnO and ZnO-CuO nanocomposite were estimated. 
B.C. Yadav, Richa Srivastava, Satyendra Singh, Anurodh Kumar and A.K.   Yadav
cond-mat.mtrl-sci