Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
J Am Chem Soc. 2012 Oct 24;134(42):17731-8. doi: 10.1021/ja307910u. Epub 2012 Oct 16.
Group IIIA elements (B, Ga, In, and Tl) have been doped into PbSe for enhancement of thermoelectric properties. The electrical conductivity, Seebeck coefficient, and thermal conductivity were systematically studied. Room-temperature Hall measurements showed an effective increase in the electron concentration upon both Ga and In doping and the hole concentration upon Tl doping to ~7 × 10(19) cm(-3). No resonant doping phenomenon was observed when PbSe was doped with B, Ga, or In. The highest room-temperature power factor ~2.5 × 10(-3) W m(-1) K(-2) was obtained for PbSe doped with 2 atom % B. However, the power factor in B-doped samples decreased with increasing temperature, opposite to the trend for the other dopants. A figure of merit (ZT) of ~1.2 at ~873 K was achieved in PbSe doped with 0.5 atom % Ga or In. With Tl doping, modification of the band structure around the Fermi level helped to increase the Seebeck coefficient, and the lattice thermal conductivity decreased, probably as a result of effective phonon scattering by both the heavy Tl(3+) ions and the increased grain boundary density after ball milling. The highest p-type ZT value was ~1.0 at ~723 K.
III A 族元素（B、Ga、In 和 Tl）已被掺杂到 PbSe 中，以提高其热电性能。系统地研究了电导率、塞贝克系数和热导率。室温 Hall 测量表明，Ga 和 In 掺杂可使电子浓度有效增加，Tl 掺杂可使空穴浓度增加到约 7×10(19)cm(-3)。在 B、Ga 或 In 掺杂的 PbSe 中未观察到共振掺杂现象。在 PbSe 中掺杂 2 原子%的 B 时，室温下获得的最大功率因子约为 2.5×10(-3)W m(-1)K(-2)。然而，B 掺杂样品的功率因子随温度升高而降低，与其他掺杂剂的趋势相反。在掺杂 0.5 原子%的 Ga 或 In 的 PbSe 中，获得了约 1.2 的品质因数（ZT）在约 873 K。通过 Tl 掺杂，费米能级附近的能带结构的修饰有助于提高塞贝克系数，晶格热导率降低，这可能是由于重 Tl(3+)离子的有效声子散射以及球磨后晶界密度的增加。在约 723 K 时，p 型 ZT 值最高约为 1.0。
