Fabrication of thermoelectric devices based on tellurides and manganites a material to device approach

Abstract

Thermoelectric materials play an important role in the day to day life of newlinemankind. They find applications in many areas including eco-friendly newlinealternatives for refrigeration/cooling, as energy harvesters for smart newlinesensors, for waste heat utilization and temperature sensors. The advent newlineof thermoelectric materials can be traced to the discovery of the Seebeck newlineeffect way back in 1821 by Thomas Seebeck. Seebeck effect is nothing newlinebut the development of a meaningful voltage if two dissimilar materials newlineare kept at a temperature gradient. Conversely if an electric potential newlineis applied between the two ends of two dissimilar materials the junction newlinecools. This is the Peltier effect and was discovered in the year 1834. newlineSeebeck effect is being effectively employed in the industry to build newlinesensors and transducers. Various types of thermocouples based on newlineIron-Constantin, Chromel-Alumel are some classic examples. newlineStricter environment protection legislation, increased concern for newlinemother earth, the need for the reduction of chlorofluorocarbon in the newlineatmosphere have all led to a revisit of the above materials. Major newlinescientific efforts in the last three to four decades have been to reduce newlinethe carbon footprint by seeking environmental friendly techniques which newlineare ozone friendly. Thus the area of thermoelectrics and Peltier cooling newlinereceived a major fillip and extensive research is being carried out in newlinethis domain. Any incremental advancement in this area produces a newlinecascading effect as far as technology is concerned. The advancementsare either through the advent of new materials or modification of newlineproperties of existing materials by substitution/doping or in the form newlineof composites. The correlation of structural properties with the various newlinephysical properties in these materials plays an important role in tailoring newlinethe material properties. This requires a thorough understanding of newlinethe underlying physics. Quantum mechanics plays a pivotal role here. newline