Power Evaluation of PbTe with Continuous Carrier Concentration Gradient
In this paper, we reported that lead telluride (PbTe) with continuous carrier concentration gradient, in which PbI2, Al and Zr were doped, were successfully fabricated by the unidirectional solidification method. The carrier concentration was optimized by adjusting the relation between the dopants and the carrier concentration gradient. The carrier concentration for the ingots was estimated from the resistance results which were measured by the one-probe method. The result shows that the carrier concentration was large at the initiation side and small at termination side of the solidified ingots. The degree of the carrier concentration gradient can be controlled by the holding time at a liquid state and the cooling rate from the liquid state. The carrier concentration gradient can be largely affected by the Al-dopant. The samples 0.07mol%PbI2-0.05mol%Zr-0.07mol%Al-PbTe, which were made from a liquid phase at 1200K held for 1h and cooled at 98K/h, showed a carrier concentration gradient ranging from 2×1024 to 1.5×1025 /m3. The effective maximum power for this continuous FGM is 20% larger than that of jointed FGM.
Omer Van der Biest, Michael Gasik, Jozef Vleugels
Y. Imai et al., "Power Evaluation of PbTe with Continuous Carrier Concentration Gradient ", Materials Science Forum, Vols. 492-493, pp. 145-150, 2005