TiFe_0.5Ni_0.5Sb-based half-Heusler compounds have the intrinsic low lattice thermal conductivity and the adjustable band structure. Inspired by the previously reports to achieve both p- and n-type components by tuning the ratio of Fe and Ni based on the same parent TiFe_0.5Ni_0.5Sb, we selected Co as the amphoteric dopants to prepare both n-type and p-type pseudo-ternary Ti(Fe, Co, Ni)Sb-based half-Heusler alloys. The carrier concentration, as well as the density of states effective mass was significantly increased by Co doping, contributing to the enhanced power factor of 1.80 mW m⁻¹ K⁻² for n-type TiFe_0.3Co_0.2Ni_0.5Sb and 2.21 mW m⁻¹ K⁻² for p-type TiFe_0.5Co_0.15Ni_0.35Sb at 973 K. Combined with the further decreased lattice thermal conductivity due to the strain field and mass fluctuation scattering induced by alloying Hf on the Ti site, peak ZTs of 0.65 in n-type Ti_0.8Hf_0.2Fe_0.3Co_0.2Ni_0.5Sb and 0.85 in p-type Ti_0.8Hf_0.2Fe_0.5Co_0.15Ni_0.35Sb were achieved at 973 K, which is of great significance for the thermoelectric power generation applications.

TiFe _0.5 Ni _0.5 Sb基半霍斯勒化合物具有固有的低晶格热导率和可调节的能带结构。受先前报道的启发，通过基于同一母体TiFe _0.5 Ni _0.5 Sb调整Fe和Ni的比例来实现p型和n型成分，我们选择Co作为两性掺杂剂来制备n型和p型准三元Ti（Fe，Co，Ni）Sb基半Heusler合金。Co掺杂显着提高了载流子浓度以及有效态态密度，从而对n型TiFe _0.3 Co _0.2 Ni _0.5的功率因数提高了1.80 mW m ^-1  K ^-2。p型TiFe _0.5 Co _0.15 Ni _0.35 Sb在973 K时的Sb和2.21 mW m ^-1  K ^-2，n型Ti _0.8 Hf _0.2 Fe _0.3 Co _0.2 Ni _0.5 Sb中0.65的峰值ZTs和p型Ti _0.8 Hf _0.2 Fe _0.5 Co _0.15 Ni _0.35 p中的0.85的峰值ZTsSb在973 K时达到，这对热电发电应用具有重要意义。