Monolytic module based on Si0.7Ge0.3 alloy for thermoelectric generator

Made n- and p-type Si0.7Ge0.3 thermoelectric alloys and their thermoelectric characteristics are studied. These alloys are cut into profiled plates, monolithic packages are assembled from them, switching plates are glued to the lower and upper bases of the packages, commutated packages are cut into 4-5 mm thick plates and monolithic thermoelectric modules are assembled from them. Electrical insulation nodes of thermoelectric modules are made on the basis of AlN and graphite plates. These nodes are connected to modules, resulting in monolithic samples. The energy characteristics of monolithic thermoelectric modules are studied.4 n- and p-type alloy plates (2 n-type and 2 p-type) were taken to make a mini monolithic thermoelectric module containing 16 branches. They were arranged in n-p-n-p order. A mini-monolithic thermoelectric module containing 24 branches was made using a similar technology. The difference is that the monolithic package is made of 6 plates.The electric power of thermoelectric modules is calculated by the electromotive force, external electric resistance and electric voltage generated by the module. On the basis of temperature dependences of specific electrical conductivity, thermal conductivity and Seebeck coefficient, values of figure of merit ZT were calculated. ZT for n-Si0.7Ge0.3 is ~25% higher than for p-Si0.7Ge0.3 at the same temperatures. An alloy of this composition, SixGe1-x (x=0.7), was chosen because it, together with highly compatible tungsten, gives a switching junction with low electrical resistance.