Mobility of Electrons and Holes in PbS, PbSe, and PbTe between Room Temperature and 4.2°K

Abstract

Hall coefficient and resistivity measurements have been made on 29 single crystals (mostly synthetic) of PbS, PbSe, and PbTe between room temperature and 4.2'K. Almost all of the samples had extrinsic carrier concentrations of the order of 10' per cm', as deduced from the Hall coefficients which were essentially constant over the entire temperature range investigated. Hall mobilities were calculated from the Hall and resistivity data, and were found to increase rapidly with decreasing temperature.Between room temperature and about 50'K the mobility behavior was essentially intrinsic and varied approximately as T~2.Below 50'K the mobility curves turned gradually toward the horizontal in a manner resembling the residual resistance phenomenon observed in metals. Values as high as 800000 cm'/v-sec were attained at 4. 2'K despite the large carrier concentrations present in all the samples. A simple experiment was performed which suggests that dislocations are the principal scattering mechanism below 50'K, rather than the charged point defects associated with the extrinsic carriers. The possibility that a high static dielectric constant could explain the large mobilities at low temperatures is discussed.

Weak electron–phonon coupling contributing to high thermoelectric performance in n-type PbSe

“…The p-type samples are selected such that the carrier density is relatively low and thus the influence from the heavy band at this temperature is negligible. It is clearly seen that the mobility of the n-type material is much higher than that of the p-type material over the entire carrier density range [there are previous studies supporting this result (34,36,37), while there are also other reports suggesting that the mobility is similar between n-and p-type PbSe at room temperature (35,38)]. Furthermore, the SKB model provides excellent prediction of μ H vs. n H at 300 K for both n-and p-type materials at high doping levels where acoustic phonon scattering is the dominant mechanism.…”

“…Fig. 5B shows the Hall mobility (μ H ) of n-and p-type samples at 300 K as well as data reported by Smirnov (34), Allgaier (35), and Androulakis (29). The p-type samples are selected such that the carrier density is relatively low and thus the influence from the heavy band at this temperature is negligible.…”

Graded Design of Carrier Concentration in Thermoelectric PbTe System by Heat-treatment

“…The value of µ is similar to the literature data, 9) which indicates an ideal purity for PbTe. After thermal exposure with a hole-doping source at 900 K for 1 h the n of the stoichiometric PbTe had increased by a factor of 5 (as shown in Table 1).…”

On mobility of electrons in a shallow Fermi sea over a rough seafloor

“…Fig. 6 presents a similar treatment of the available data on PbTe [32,17] and BiTlSeS, which was the subject of a recent study. Novak et al [45] quantified mobility as a function of concentration in a system with a vanishing gap tuned half-way between BiTlSe 2 and BiTlS 2 , two band insulators (one trivial and one topological) with gaps of comparable amplitudes [46].…”

“…The key parameter remains the Bohr radius of the host insulator, which by setting the Thomas-Fermi screening length, shapes the local seafloor of the Fermi sea. The reported data for phosphorus-doped silicon [28], arsenic-doped [29], antimony-doped [30] and gallium-doped [31] germanium are presented together with those for p-doped [17,32] and n-doped [32] PbTe, as well as for oxygen-deficient SrTiO 3 [14,33,34,35]. The figure reveals several remarkable features.…”