Defect Reconfiguration in Hole-Doped PbSe via Minute Te Doping for Significantly Enhanced Thermoelectric Performance

Abstract

Rich defects near the percolation threshold of dilute solid solutions are of fundamental interest to thermoelectric research. Snsubstituted Pb 0.98 Na 0.02 Se (1 mol %) is a typical example that demonstrates how various defects induce intriguing transport phenomena. Unfortunately, the presence of Pb vacancies severely degrades the carrier mobility of samples, and the thermoelectric figure of merit ZT is only marginally improved. In this study, we show that Pb vacancies are effectively inhibited by a facile defect reconfiguration strategy. This is achieved by doping a dilute amount of Te at Se sites of Pb 0.97 Sn 0.01 Na 0.02 Se, where the interstitial Sn ions are pulled back to Pb sites as revealed by the X-ray photoelectron spectroscopy analysis and the positron annihilation test. Consequently, Pb vacancies get occupied, and the room temperature carrier mobility is remarkably recovered from 2.8 to 70 cm 2 V −1 s −1 upon 3 mol % Te doping. Moreover, Te doping reinforces phonon scattering by strain and mass field fluctuations. The lattice thermal conductivity at 300 K goes down to ∼1.7 W m −1 K −1 for Pb 0.97 Sn 0.01 Na 0.02 Se 0.94 Te 0.06 , which is ∼32% lower than that of the Pb 0.97 Sn 0.01 Na 0.02 Se control sample. Altogether, the average ZT value of Pb 0.97 Sn 0.01 Na 0.02 Se between 300 and 773 K is doubled upon 6 mol % Te doping.

Optimization of Carrier Concentration in Cu22Sn10S32 through In- and Zn-Doping for Enhanced Thermoelectric Performance

“…The substitution of In or Zn on the Cu lattice sites may suppress the formation of Cu vacancies, which results in the increase of τ 2 and, simultaneously, the decrease of I 2 . This has been reported in other systems as well. , …”

“…This has been reported in other systems as well. 39,40 Electrical Transport Properties. The temperature dependence of electrical transport performance (σ and S) for Cu 22−x In x Sn 10 S 32 and Cu 22−y Zn y Sn 10 S 32 is shown in Figure 5a,b.…”

Controlling Precipitation and Dopant Effects To Achieve Promising Thermoelectric Performance in CaTiO3

“…1 The conversion efficiency of TE materials is assessed using the equation zT = S 2 σT/κ, where S, σ, T, and κ are the Seebeck coefficient, electrical conductivity, absolute temperature, and thermal conductivity, respectively. 2 Significant progresses have been made in diverse TE systems, including Bi 2 Te 3 , 3 PbTe, 4 GeTe, 5 SnTe, 6 SnSe, 7 PbSe, 8 Cu 2 Se, 9 SiGe, 10 CoSb 3 , 11 half-Heusler, 12 and Zintls phase. 13 Perovskite-type oxide TE materials have been recognized as a potential candidate for application in TE power generation because of their advantages of high thermal and chemical stability at high temperatures, easy manufacture, and low cost.…”