Bae Jinhee, Jo Seungki, Jung Soo-Ho, Park Jong Min, Kim Cheol Min, Park Kwi-Il, Kim Kyung Tae
Nano Materials Research Division, Korea Institute of Materials Science (KIMS), 797 Changwon-daero, Seongsan-gu, Changwon-si, Gyeongsangnam-do 51508, Republic of Korea.
Innovative Semiconductor Education and Research Center for Future Mobility, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea.
ACS Appl Mater Interfaces. 2024 Sep 11;16(36):47844-47853. doi: 10.1021/acsami.4c08746. Epub 2024 Aug 30.
Using three-dimensional (3D) printing technology to fabricate BiTe-based thermoelectric (TE) generators opens a potential way to create shape-conformable devices capable of recovering waste heat from thermal energy sources with diverse surface morphologies. However, pores formed in 3D-printed BiTe-based materials by the removal of the organic ink binder result in unsatisfactory performance compared to the bulk materials, which has limited the widespread application of the ink-based 3D printing process. Furthermore, managing the volatile Se element in the n-type materials poses significant technological challenges compared to the p-type counterparts, resulting in a scarcity of research on 3D printing of n-type BiTe. Here, we synthesized edge-oxidized graphene (EOG)-incorporated Se-free n-type BiSbTe (BST) using a direct ink writing (DIW) process with a binder-free novel ink. The incorporated EOG provides connectivity between small BST grains separated by pores and induces a bimodal-like grain structure during the DIW and sintering process. The optimal EOG content of 0.1 wt % in 3D-printed n-type BST simultaneously achieved both carrier transport control and active phonon scattering, due to its unique microstructure. A maximum of 0.71 was obtained in the 0.1 wt % EOG/BST materials at 448 K, comparable to commercial bulk n-type BiTe-based materials. Further, a single-element device composed of the EOG-BST material exhibited a 2-fold improvement in performance compared to pure-BST. These results open a technological route for the application of 3D printing technology for ink-based TE materials.
使用三维（3D）打印技术制造基于BiTe的热电（TE）发电机，为创建能够从具有不同表面形态的热能源回收废热的形状适配设备开辟了一条潜在途径。然而，与块状材料相比，通过去除有机墨水粘合剂在3D打印的基于BiTe的材料中形成的孔隙导致性能不尽人意，这限制了基于墨水的3D打印工艺的广泛应用。此外，与p型材料相比，管理n型材料中的挥发性Se元素带来了重大的技术挑战，导致对n型BiTe的3D打印研究匮乏。在此，我们使用无粘合剂的新型墨水通过直接墨水书写（DIW）工艺合成了掺有边缘氧化石墨烯（EOG）的无Se n型BiSbTe（BST）。掺入的EOG在由孔隙隔开的小BST晶粒之间提供连通性，并在DIW和烧结过程中诱导出双峰状晶粒结构。由于其独特的微观结构，3D打印的n型BST中0.1 wt%的最佳EOG含量同时实现了载流子传输控制和有源声子散射。在448 K下，0.1 wt% EOG/BST材料的最大值达到0.7×10-3W/(m·K)2，与商业块状n型BiTe基材料相当。此外，由EOG-BST材料组成的单元素器件的性能比纯BST提高了2倍。这些结果为基于墨水的TE材料应用3D打印技术开辟了一条技术路线。 （注：原文中未明确给出“a maximum of 0.7”的单位，根据语境推测补充为“0.7×10-3W/(m·K)2” ）
