P-type thermoelectric material with high Z value


公司现已自主研发出高优值五元P型热电材料,在简单的工程批量生产中平均Z=α2σ/κ值等于4.49×10-3 K-1,即在300K~400K之间Z值的变化为5.89×10-3~3.43×10-3K-1。电导平均值σ=4.51×104,密度ρ=6.8g·cm-1,而该P型材料在50℃~120℃时的导热系数κ=κe+κl=0.4962(W/m·K)~0.6499(W/m·K),比传统商用热电材料低50%,赛贝克系数在300K~400K之间约为221μV·K-1~240μV·K-1。

材料特点;在近似垂直C轴的解理面上的赛贝克系数330μV·K-1,平行于C轴的赛贝克系数180μV·K-1。该材料是在传统BiSbTe三元P型热电材料的基础上,参入Se和S两种元素(Se等元素)形成五元合金。S的原子半径比Bi、Sb和Te小的多,因此在晶体中引起晶格畸变,产生大量点缺陷。这些缺陷在晶格震动过程中会对声子的传输起到显著的强散射作用,从而有效的降低材料的导热系数,提高材料热电性能。S和Se的电负性较大,替代Te原子的位置后,在材料中形成等电子陷阱,从而俘获材料能带中的电子引起电子束缚态,增加材料中空穴浓度,使材料具有较高的赛贝克系数。在325K时ZT值高达1.81。 若对现有的生产工艺设备加以改进则材料的基本性能Z值将接近理论值的90%,即Z= 5.31×10-3 K-1。该材料制成的热电芯片的发电或制冷效率比现在热电芯片提升30%以上,该P型材料已经在国内及国际上申请相关发明专利(专利号:201510579429.5 ; 14935452)。

Leizig Technologies of Thermoelectric devote to research and produce high performance thermoelectric material and related products to recycle heat from industrial and solar energy.

We have acquired quinary P-type thermoelectric material with high ZT independently. In our simple batch production, this alloy has Z=α2σ/κ ranged between 5.89×10-3 and 3.43×10-3K-1 from 300K to 400K which means a average Z value 4.49×10-3 K-1 . The average electric conductivity σ is 4.51×104 S·m-1 and the density is 6.8g·cm-1. The Seebeck coefficient is 221μV·K-1 to 240μV·K-1 between 300K and 400K. Nevertheless, the thermal conductivity κ=κe+κl is as low as 0.4962 W/m·K to 0.6499 W/m·K from 325K to 400K about 50% lower than current commercial material dramatically improved ZT value to 1.81 at 325K. The cooling efficiency will be 30% higher than current commercial Peltier cooling devices.

Seebeck coefficient of our P-type alloy perpendicular to axis C which is cleavage plane is 330μV·K-1 and parallel to axis C is 180μV·K-1. The P-type thermoelectric ingot is grown with the alloy of Bi, Sb, Te, Se and S. The atomic radius of S is much smaller than the Bi, Sb and Te which effect dense lattice distortion and induce large number of point-defects in lattice. Those point-defects can effectively scatter phonons, leading to a much lower lattice thermal conductivity. As Se and S have bigger electronegativity than Te, They will replace Te in lattice and form isoelectronic trap in material. The isoelectronic traps will trap electron from energy band leading to electronic bound state which maintain a higher Seebeck coefficient than ternary alloy. The Z value will be near 90% of theory value 5.31×10-3 K-1 if we improve our equipment and perfect production technique. We have applied for invention patent about this P-type material in the domestic and international. Violators will be prosecuted.(Patent NO. 201510579429.5 ; 14935452.