Thermoelectric phenomena, which involve the direct and mutual conversion of heat and electricity without any combustion or mechanical process, could play an important role in a global sustainable energy solution. However, the low efficiency of the traditional thermoelectric materials has limited their usage in space-based or other niche applications. Recently, nanoscale phenomena are successfully applied to develop thermoelectric materials with enhanced room temperature performance. We have studied thermoelectric properties (Seebeck coefficient and electrical conductivity) of novel thermoelectric alloys: AgSbTe2 and AgSbSe2 by combining first-principles calculations and semiclassical Boltzmann theory of transport. Currently, we are studying the thermoelectric properties of (AgSbTe2)n/(AgSbSe2)n superlattices.