Lead sulfide(PbS)presents large potential in thermoelectric application due to its earth-abundant S element.However,its inferior average ZT(ZTave)value makes PbS less competitive with its analogs PbTe and PbSe.To prom...Lead sulfide(PbS)presents large potential in thermoelectric application due to its earth-abundant S element.However,its inferior average ZT(ZTave)value makes PbS less competitive with its analogs PbTe and PbSe.To promote its thermoelectric performance,this study implements strategies of continuous Se alloying and Cu interstitial doping to synergistically tune thermal and electrical transport properties in n-type PbS.First,the lattice parameter of 5.93Åin PbS is linearly expanded to 6.03Åin PbS_(0.5)Se_(0.5)with increasing Se alloying content.This expanded lattice in Se-alloyed PbS not only intensifies phonon scattering but also facilitates the formation of Cu interstitials.Based on the PbS_(0.6)Se_(0.4)content with the minimal lattice thermal conductivity,Cu interstitials are introduced to improve the electron density,thus boosting the peak power factor,from 3.88μW cm^(−1)K^(−2)in PbS_(0.6)Se_(0.4)to 20.58μW cm^(−1)K^(−2)in PbS0.6Se0.4−1%Cu.Meanwhile,the lattice thermal conductivity in PbS_(0.6)Se_(0.4)−x%Cu(x=0-2)is further suppressed due to the strong strain field caused by Cu interstitials.Finally,with the lowered thermal conductivity and high electrical transport properties,a peak ZT~1.1 and ZTave~0.82 can be achieved in PbS_(0.6)Se_(0.4)−1%Cu at 300–773K,which outperforms previously reported n-type PbS.展开更多
基金National Science Fund for Distinguished Young Scholars,Grant/Award Number:51925101National Natural Science Foundation of China,Grant/Award Number:52172236+1 种基金Fundamental Research Funds for the Central Universities,Grant/Award Number:xtr042021007Top Young Talents Programme of Xi'an Jiaotong University。
文摘Lead sulfide(PbS)presents large potential in thermoelectric application due to its earth-abundant S element.However,its inferior average ZT(ZTave)value makes PbS less competitive with its analogs PbTe and PbSe.To promote its thermoelectric performance,this study implements strategies of continuous Se alloying and Cu interstitial doping to synergistically tune thermal and electrical transport properties in n-type PbS.First,the lattice parameter of 5.93Åin PbS is linearly expanded to 6.03Åin PbS_(0.5)Se_(0.5)with increasing Se alloying content.This expanded lattice in Se-alloyed PbS not only intensifies phonon scattering but also facilitates the formation of Cu interstitials.Based on the PbS_(0.6)Se_(0.4)content with the minimal lattice thermal conductivity,Cu interstitials are introduced to improve the electron density,thus boosting the peak power factor,from 3.88μW cm^(−1)K^(−2)in PbS_(0.6)Se_(0.4)to 20.58μW cm^(−1)K^(−2)in PbS0.6Se0.4−1%Cu.Meanwhile,the lattice thermal conductivity in PbS_(0.6)Se_(0.4)−x%Cu(x=0-2)is further suppressed due to the strong strain field caused by Cu interstitials.Finally,with the lowered thermal conductivity and high electrical transport properties,a peak ZT~1.1 and ZTave~0.82 can be achieved in PbS_(0.6)Se_(0.4)−1%Cu at 300–773K,which outperforms previously reported n-type PbS.
