Power generation and thermoelectric cooling enabled by momentum and energy multiband alignments

Thermoelectric materials transfer heat and electrical energy, hence they are useful for power generation or cooling applications. Many of these materials have narrow bandgaps, especially for cooling applications. We developed SnSe crystals with a wide bandgap (E-g approximate to 33 k(B)T) with attractive thermoelectric properties through Pb alloying. The momentum and energy multiband alignments promoted by Pb alloying resulted in an ultrahigh power factor of similar to 75 mu W cm(-1) K-2 at 300 K, and an average figure of merit ZT of similar to 1.90. We found that a 31-pair thermoelectric device can produce a power generation efficiency of similar to 4.4% and a cooling Delta T-max of similar to 45.7 K. These results demonstrate that wide-bandgap compounds can be used for thermoelectric cooling applications.