摘要
It has been proved that the thermoelectric performance of p-type SnSe crystals can be optimized through enhancing carrier concentration.The calculations of electronic band structure elucidate that this approach can be interpreted by including multiple valence bands.To better estimate the potential performance,we proposed the transport properties for p-type SnSe crystals and analyzed the weighted mobility from the experimental results.The weighted mobility approaches~600 cm^(2)V1s1 when the carrier concentration is as high as~6.31019 cm3.Combined with obtained lattice thermal conductivity,through rising carrier concentration,the quality factor B possesses significant improvements of~235%and 138%at 300 K and 773 K,respectively.Through comparing weighted mobility and Hall mobility,two effective mass values~0.9 me and 1.8 me can be derived using carrier concentrations.It is expected that the ZT~1.0 at 300K and ZT~2.9 at 773 K can be obtained when the carrier concentration of~8.01019 cm3 and the effective mass~1.8 me were selected.This work provides an alternative way to comprehend the performance optimization in thermoelectric community.
基金
the National Key Research and Development Program of China(2018YFA0702100 and 2018YFB0703600)
the National Natural Science Foundation of China(51632005 and 51772012)
the Beijing Natural Science Foundation(JQ18004)
the Shenzhen Peacock Plan team(KQTD2016022619565991)
111 Project(B17002).L.D.Z.thanks for the support from the National Science Fund for Distinguished Young Scholars(51925101).