The new material, based on the common semiconductor lead telluride
, is the most efficient thermoelectric material known.
These include 15 minerals containing gold and/or silver and 14 tellurides, among which are the lead telluride
altaite, the mercury telluride coloradoite, and the nickel telluride melonite.
Extending their work on lead-based dots, the NREL researchers report in the March 15 Journal of the American Chemical Society that lead telluride
dots produce up to three excitons from single solar-energy photons.
A number of thermoelectric materials have been developed for various operating temperature ranges: bismuth telluride and bismuth selenide alloys for lower-temperature (approximately room temperature) applications, lead telluride alloys for intermediate 200[deg] to 500[deg] C) applications, and silicon germanium alloys for high temperature (400[deg] to 1000[deg] C).
Thermoelectric converter power systems using a unicouple configuration have flown on several noteworthy missions, including Pioneers 10 and 11, which had lead telluride thermoelectric material converters, and Voyagers I and II, which used silicon geranium-based thermoelectrics.
To make this possible, the team dispersed nanocrystals of rock salt (SrTe) into the material lead telluride
To make the lattice, Springholz and his colleagues lay down alternating layers of lead telluride
sheets and arrays of pyramid-shaped dots of lead selenide.
Besides bismuth telluride, two other materials and their associated derivatives came to the forefront during those early research years: lead telluride
and silicon-germanium alloys.