Liang Chongbin, Jabar Bushra, Liu Chen, Chen Yuexing, Zheng Zhuanghao, Fan Ping, Li Fu
Shenzhen Key Laboratory of Advanced Thin Films and Applications, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
Nanomaterials (Basel). 2022 Jul 15;12(14):2434. doi: 10.3390/nano12142434.
The Te-free compound Bi2SeS2 is considered as a potential thermoelectric material with less environmentally hazardous composition. Herein, the effect of iodine (I) substitution on its thermoelectric transport properties was studied. The electrical conductivity was enhanced due to the increased carrier concentration caused by the carrier provided defect Ise. Thus, an enhanced power factor over 690 μWm−1K−2 was obtained at 300 K by combining a moderate Seebeck coefficient above 150 µV/K due to its large effective mass, which indicated iodine was an effective n-type dopant for Bi2SeS2. Furthermore, a large drop in the lattice thermal conductivity was observed due to the enhanced phonon scattering caused by nanoprecipitates, which resulted in a low total thermal conductivity (<0.95 Wm−1K−1) for all doped samples. Consequently, a maximum ZT value of 0.56 was achieved at 773 K for a Bi2Se1−xIxS2 (x = 1.1%) sample, a nearly threefold improvement compared to the undoped sample.
不含碲的化合物Bi2SeS2被认为是一种潜在的热oelectric材料，其成分对环境危害较小。在此，研究了碘（I）取代对其热electric输运性质的影响。由于由缺陷Ise提供的载流子导致载流子浓度增加，电导率得到提高。因此，由于其较大的有效质量，在300 K时通过结合高于150 µV/K的适度塞贝克系数，获得了超过690 μWm−1K−2的增强功率因数，这表明碘是Bi2SeS2的有效n型掺杂剂。此外，由于纳米沉淀物引起的声子散射增强，观察到晶格热导率大幅下降，这导致所有掺杂样品的总热导率较低（<0.95 Wm−1K−1）。因此，对于Bi2Se1−xIxS2（x = 1.1%）样品，在773 K时实现了0.56的最大ZT值，与未掺杂样品相比提高了近三倍。
