Recently, one-dimensional van der Waals crystal Ta₄SiTe₄ has been reported as a promising low-temperature thermoelectric material. Extraordinarily high power factor has been reported for the one-dimensional Ta₄SiTe₄ single whisker and two-dimensional (PVDF)/Ta₄SiTe₄ composite film, but the thermoelectric properties of three-dimensional Ta₄SiTe₄ polycrystalline bulks have been rarely investigated. In this study, we prepared a series of phosphorus (P)-doped Ta₄SiTe₄ polycrystalline bulks by using the high-temperature synthesis and cold press method. Their electrical and thermal transport properties along the directions parallel and perpendicular to the pressure were systematically investigated. Upon doping P at the Si-sites to increase the carrier concentration, the electrical conductivity is enhanced while the intrinsic excitation is suppressed, resulting in significantly improved power factor approaching the theoretically optimal value. All Ta₄Si_1-xP_xTe₄ bulks possess low lattice thermal conductivities with the values below 1.2 Wm⁻¹K⁻¹. The weak van der Waals interaction among the [Si₂Ta₈Te₈]_n chains results in the appearance of low-lying optical modes and introduces additional scattering to phonons. A peak thermoelectric figure of merit value of 0.18 is obtained at 300 K for polycrystalline Ta₄Si_0·995P_0·005Te₄, about double that of pristine polycrystalline Ta₄SiTe₄.

近来，一维范德华晶体Ta ₄ SiTe ₄被报道为有前途的低温热电材料。对于一维Ta ₄ SiTe ₄单晶须和二维（PVDF）/ Ta ₄ SiTe ₄复合膜，已经报道了极高的功率因数，但是很少有三维Ta ₄ SiTe ₄多晶体的热电性能。调查。在这项研究中，我们制备了一系列掺磷（P）的Ta ₄ SiTe ₄通过使用高温合成和冷压法制备多晶体。系统地研究了它们在平行于和垂直于压力的方向上的电和热传输特性。通过在Si位点掺杂P以增加载流子浓度，可以提高电导率，同时抑制本征激发，从而使功率因数显着提高，接近理论上的最佳值。所有的Ta ₄ Si _{1- x} P _x Te ₄块体都具有较低的晶格热导率，其值低于1.2 Wm ^-1 K ^-1。[Si ₂ Ta ₈Te ₈ ] _n链导致出现低层光学模式，并向声子引入额外的散射。对于多晶Ta ₄ Si _0·995 P _0·005 Te ₄，在300 K下获得的峰值热电品质因数值为0.18 ，约为原始多晶Ta ₄ SiTe _4的两倍。