The Bi₂O₂Se-based compounds with an intrinsically low thermal conductivity and relatively high Seebeck coefficient are good candidates for thermoelectric application. However, the low electrical conductivity resulted from carrier concentration of only 10¹⁵ cm⁻³ for pristine material, which is too low for optimized thermoelectrics. As a result, the carrier concentration optimization of Bi₂O₂Se is important and useful to achieve higher power factor. In this work, the effect of Ge-doping at the Bi site has been investigated systematically, with expectations of carrier concentration optimization. It is found that Ge doping is an efficient method to increase carrier concentration. Due to the largely increased carrier concentration via Ge doping, the room temperature electrical conductivity rises rapidly from 0.03 S/cm in pristine sample to 133 S/cm in x = 0.08 sample. Combined with the intrinsically low thermal conductivity, a maximum ZT value of 0.30 has been achieved at 823 K for Bi_1.92Ge_0.08O₂Se, which is the highest ZT value for Bi₂O₂Se-based thermoelectric materials.

具有本质上低的热导率和相对高的塞贝克系数的Bi ₂ O ₂ Se基化合物是热电应用的良好候选者。但是，低电导率是由于原始材料的载流子浓度仅为10 ¹⁵  cm ^-3，对于优化的热电而言太低了。结果，Bi ₂ O ₂的载流子浓度最优化Se对于实现更高的功率因数是重要且有用的。在这项工作中，系统地研究了Bi部位Ge掺杂的影响，并期望能优化载流子浓度。发现Ge掺杂是增加载流子浓度的有效方法。由于通过Ge掺杂大大增加了载流子浓度，因此室温电导率从原始样品中的0.03 S / cm迅速增加到x = 0.08样品中的133 S / cm。结合固有的低导热性，Bi _1.92 Ge _0.08 O ₂ Se在823 K时最大ZT值为0.30 ，这是Bi ₂ O ₂的最高ZT值硒基热电材料。