Sm-substitution effects on structural and transport properties of PbSe

Effect of heat treatment on the electrical and thermoelectric properties of Sb doped Bi2Se3

“…This scenario does not alter when either the temperature or annealing time is changed. The Seebeck coefficient possesses negative values over the whole temperature range of measurements, confirming n-type conduction, which agrees well with other reported results [30] for bismuth selenide compounds.…”

“…In general, the overall behavior of the samples does not vary with variation of the annealing temperature or time and the σ-T plots exhibit a conduction transition at a certain temperature Tσ. To be specific, in the low temperature range (100 ⩽ T ⩽ Tσ), σ decreases with increasing temperature and the behavior is characterized by semi-metallic conduction attributed to the carrier scattering process [1,14,[30][31][32]. In the high temperature range, above Tσ, the conductivity increases with increasing ambient temperature, suggesting an intrinsic semiconducting mechanism [27].…”

“…The behavior of ΔE and σ 300 with the annealing temperature change can be explained by invoking the influence of bismuth super-stoichiometry and the Sb content on the concentration of the lattice point defects occurring in the (Bi 1−x Sbx) 2 Se 3 crystal lattice. The super-stoichiometric bismuth content in the undoped Bi 2 Se 3 crystals gives rise to ntype electrical conduction behavior due to the presence of positively charged vacancies in the selenium sublattice [30]. The excess of Bi in the crystal also results in the formation of antisite defects (having negative charge) in the lattice due to the replacement of the selenium atoms in their lattice sites by bismuth atoms.…”

Transport properties of the system Bi2Te2.7Se0.3−xPbxfabricated by a conventional melting technique

“…No indication of impurities or secondary phases denoting other Bi-Te-Se-Pb compounds could be observed. This may be reasonable because in Bi 2 Te 2.7 Se 0.3−x Pb x the Te and Bi atoms can be substituted by Se and Pb atoms, respectively, and crystallize in the same rhombohedral Bi 2 Te 3 structure, while a high temperature is needed to form PbTe and PbSe phases in a rock-salt-type crystal structure [20][21][22]. Furthermore, the formation of ternary and quaternary phases requires high dopant concentration and high syntheses pressure [23,24], which are not realized in this work.…”

Influence of Yb-doping on the thermoelectric properties of Pb1−xYbxTe alloy synthesized using solid-state microwave

“…This behavior due to polycrystalline thin films can be explained by the grain boundary trapping according to Baccarani [29]. There are a large number of defects in the grain boundaries because of incomplete atomic bonding [30]. The Yb-doping produces the formation of density of states near the Fermi level; these densities of state oppose and reduce the electrical conduction by capturing the charge carriers at the low-temperature region.…”