Fabrication and characterization of Pb_(1-x)Yb_xTe-based alloy thin-film thermoelectric generators grown by thermal evaporation technique

摘要

In this study p-Pb_(0.925)Yb_(0.075)Te:Te and n-Pb _(0.94)Yb_(0.06)Te powders synthesized by solid-state microwave technique were used to fabricate thermally evaporated thin films. The nanostructure and composition of the films were studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDX). Electrical characterizations of the as-deposited films in terms of the Seebeck coefficient and electrical conductivity and power factor were conducted at a range of 298 K to 523 K. The microthermoelectric devices were composed of 20-pair and 10-pair p-Pb_(0.925)Yb _(0.075)Te:Te and n-Pb_(0.94)Yb_(0.06)Te thin films on glass substrates. The dimensions of the thin-film thermoelectric generators, which consisted of 20-pair and 10-pair legs connected by aluminum electrodes, were 23 mm×20 mm and 12 mm×10 mm, respectively. The 20-pair p-n thermocouples in series generated a maximum open-circuit voltage output (V _(oc)) of 0.581 V and a maximum output power of 25.87×10 ~(-8) W at a temperature difference ΔT=164 K, whereas the 10-pair p-n thermocouples generated 0.311 V and 13.71×10~(-8) W maximum V_(oc) and maximum output power, respectively, at ΔT=164 K.