英语翻译Although Seebeck observed thermoelectric phenomena in 18

英语翻译
Although Seebeck observed thermoelectric phenomena in 1821 and Altenkirch defined the ZT equation in 1911,ittook several decades to develop the first functioning devices in the 1950s and1960s.4 They are now called the firstgeneration thermoelectrics with an average ZT of 1.0,and devices madeof them can operate at 4–6% conversion efficiency.Following several moredecades of stagnancy,new theoretical ideas relating to size effects on thethermoelectric properties in the 1990’s stimulated new experimental researchthat eventually led to significant advances in the following decade.Althoughthe theoretical ideas were originally about predictions on raising the powerfactor,the experimental breakthroughs were achieved by significantlydecreasing the (lattice) thermal conductivity.1,2,5–8 Among a wide variety of research approaches,one hasemerged,which has led to a near doubling of the ZT at high temperaturesand has defined the second generation of bulk thermoelectric materials with ZT in the range of 1.3–1.7.This approach uses nanoscale precipitates and compositional inhomogeneities todramatically suppress the lattice thermal conductivity.1,2,7,9,10 These second generation materials are expected toproduce power generation devices with conversion efficiencies of 11–15%.