Optical properties of Pb_1-xMn_xTe

Thermopower enhancement in Pb1−xMnxTe alloys and its effect on thermoelectric efficiency

“…31 Additionally, alloys of PbTe with isovalent elements can also adjust the energy offset between the two-valence bands leading to similar band-tuning effects. 3,5,29,[32][33][34][35][36][37][38][39][40] In the case of Pb 1 Àx Mg x Te, the roomtemperature band gap increases with increasing Mg content, meaning the energy of the light valence band is reduced to achieve an effective alignment with the heavy band even at room temperature. 5,[33][34][35] This is an opposite effect to the PbTe 1 Àx Se x alloys, which has a slightly lower band gap that produces band alignment at higher temperatures.…”

“…Such resonant state effects are not expected in isovalent alloys of MgTe or PbSe. 2 Alloying of PbTe with MnTe also modifies the band structure [38][39][40] and therefore the transport properties. 32,37 It is not entirely clear whether Mn is electrically inactive 2 that only leads to small adjustments of the band energies (as has been assumed for PbSe and MgTe alloys), or whether transport property modifications are due to a resonant state effect from the possible multiple valencies in Mn compounds.…”

Raman spectra of Pb1−xMnxTe alloys

“…Pb 1−x Mn x Te ternary alloy is one more candidate for studying this subject. Pb 1−x Mn x Te is a semimagnetic semiconductor that has not been sufficiently studied [11][12][13][14][15]. If the Mn concentration is less than 12 at.%, Mn enters the PbTe lattice as Mn 2+ and is not an electroactive dopant.…”

“…In some cases, this interaction gives rise to a small negative magnetoresistance effect [13]. No significant influence of the Mn concentration on the lattice dynamical and hence on the dielectric properties is found for Mn concentration less than 2 at.% [14].…”

Thermoelectric properties of Pb0.75−xMnxSn0.25Te alloys with variable manganese content

“…The band gaps have also been calculated from the Seebeck data (shown by black symbols), assuming equal mobility of both the holes as well as the carriers, using the formula E g ¼2eS max T max and the values obtained were between 0.22 and 0.24 eV. The experimental band gap increases with increase in Mn content, similar to PbTe since MnTe is a wide band gap material [32,33], though the increment is lower than theoretically expected. This could crossover to the n-type behavior.…”