The stereochemical expression of ns² lone-pair electrons in specific Ⅳ-Ⅵ group semiconductors is pivotal to lattice instability, which induces ferroelectric phase transition. In the thermoelectric device working temperature range, the distinct change of thermal expansion coefficient, however, is introduced by phase transition and then severely restrains material's critical applications. Herein, taking the example of thermoelectric GeTe, the hidden role of manipulating lone pair expression to control the crystal structure is theoretically unraveled. Moreover, it is experimentally demonstrated that LiBiTe₂-alloyed GeTe possess a room-temperature cubic structure and competitive thermoelectric performance. Density functional theory calculations reveal that reducing the charge orientation caused by the stereochemical activity of cation lone-pair electrons in GeTe is an effective strategy to achieve room-temperature cubic structure. LiBiTe₂ is found to be a novel alloying agent to realize crystal structure manipulating, carrier concentration optimization, multi-band convergence, and lattice softening. Benefiting from the optimized electrical and thermal transport properties, an ultrahigh ZT_ave of 1.22 within 300–773 K in cubic (GeTe)_0.80(LiBiTe₂)_0.20 is achieved. This work provides a new insight into manipulating lone pair expression to control crystal structure, and promotes the development and application of cubic GeTe-based materials.

特定 Ⅳ-Ⅵ 族半导体中 n s ²孤对电子的立体化学表达是晶格不稳定性的关键，晶格不稳定性会导致铁电相变。然而，在热电器件的工作温度范围内，热膨胀系数的明显变化是由相变引入的，从而严重限制了材料的关键应用。在此，以热电 GeTe 为例，理论上揭示了操纵孤对表达来控制晶体结构的隐藏作用。此外，实验证明 LiBiTe ₂-合金化GeTe具有室温立方结构和具有竞争力的热电性能。密度泛函理论计算表明，降低 GeTe 中阳离子孤对电子的立体化学活性引起的电荷取向是实现室温立方结构的有效策略。LiBiTe ₂被发现是一种新型合金剂，可实现晶体结构操纵、载流子浓度优化、多能带收敛和晶格软化。得益于优化的电和热传输特性，在 300–773 K 立方 (GeTe) _0.80 (LiBiTe ₂ ) _{0.20内的超高}ZT _{ave为 1.22}已完成。这项工作为操纵孤对表达以控制晶体结构提供了新的见解，并促进了立方GeTe基材料的开发和应用。