• Mamakhel, Aref
• Hedegaard, Ellen M. J.
• Reardon, Hazel

Abstract

<p>Functionally graded (PbTe)1-x(SnTe)x ingots have been prepared by Bridgman crystal growth method for the first time. From SEM-EDX, the composition (x) of the ingot was found to increase smoothly from 10.6 to 25.4 along the direction of the growth. The gradual change in composition is shown to cause a decrease in band gap as crystallization proceeds, and to be accompanied by a change in carrier concentration. By a Potential Seebeck Microprobe (PSM), a smoothly varying Seebeck coefficient was measured along the growth direction of the sample at room temperature. High temperature properties relevant for thermoelectric performance were measured and used to evaluate the potential of this system as a functionally graded high temperature thermoelectric material. This study provides insight into understanding the complicated interplays of advanced crystal growth and physical properties, going beyond standard thermoelectric sample preparation approaches.</p>

Topics

• impedance spectroscopy
• scanning electron microscopy
• Energy-dispersive X-ray spectroscopy
• crystallization