Hernandez Jose A, Ruiz Angel, Fonseca Luis F, Pettes Michael T, Jose-Yacaman Miguel, Benitez Alfredo
Department of Physics, University of Puerto Rico, Rio Piedras Campus, San Juan, PR, 00931, USA.
Department of Mechanical Engineering and Institute of Materials Science, University of Connecticut, Storrs, CT, 06269-3139, USA.
Sci Rep. 2018 Aug 10;8(1):11966. doi: 10.1038/s41598-018-30450-5.
Tin selenide (SnSe) has been the subject of great attention in the last years due to its highly efficient thermoelectricity and its possibilities as a green material, free of Pb and Te. Here, we report for the first time a thermoelectricity and transport study of individual SnSe micro- and nano-wires with diameters in the range between 130 nm and 1.15 μm. X-ray diffraction and transmission electron microscopy analyses confirm an orthorhombic SnSe structure with Pnma (62) symmetry group and 1:1 Sn:Se atomic ratio. Electrical and thermal conductivity and the Seebeck coefficient were measured in each individual nanowire using a specialized suspended microdevice in the 150-370 K temperature range, yielding a thermal conductivity of 0.55 Wm K at room temperature and ZT ~ 0.156 at 370 K for the 130 nm diameter nanowire. The measured properties were correlated with electronic information obtained by model simulations and with phonon scattering analysis. The results confirm these structures as promising building blocks to develop efficient temperature sensors, refrigerators and thermoelectric energy converters. The thermoelectric response of the nanowires is compared with recent reports on crystalline, polycrystalline and layered bulk structures.
近年来，硒化锡（SnSe）因其高效的热电性能以及作为不含铅和碲的绿色材料的潜力而备受关注。在此，我们首次报道了对直径在130纳米至1.15微米之间的单个SnSe微米线和纳米线的热电性能及输运研究。X射线衍射和透射电子显微镜分析证实了具有Pnma（62）对称群和1:1锡与硒原子比的正交晶系SnSe结构。使用专门的悬浮微器件在150 - 370K温度范围内对每根单独的纳米线测量了电导率、热导率和塞贝克系数，对于直径为130纳米的纳米线，室温下热导率为0.55WmK，在370K时ZT约为0.156。所测量的性能与通过模型模拟获得的电子信息以及声子散射分析相关联。结果证实这些结构是开发高效温度传感器、制冷器和热电能量转换器的有前景的构建单元。将纳米线的热电响应与最近关于晶体、多晶和层状块状结构的报道进行了比较。
