Department of Physics, University of South Florida, Tampa, Florida 33620, United States.
ACS Appl Mater Interfaces. 2015 May 13;7(18):9752-7. doi: 10.1021/acsami.5b01617. Epub 2015 Apr 29.
Cu2ZnSnSe4 and Ag2ZnSnSe4 nanocrystals were synthesized by a colloidal synthesis route and subsequently densified to form dense polycrystalline bulk specimens with nanoscale grains employing spark plasma sintering (SPS). Powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and electron diffraction spectroscopy (EDS) were used to characterize the nanocrystals. The optical bandgap, thermal stability, and low temperature transport properties of the nanostructured polycrystalline stannites Cu2ZnSnSe4 and Ag2ZnSnSe4 were investigated. The transport properties of Ag2ZnSnSe4 are reported here for the first time and indicate polaronic-type conduction. Cu2ZnSnSe4 is p-type while Ag2ZnSnSe4 is n-type. The thermal transport in these materials is also investigated, the thermal conductivity of nanostructured Cu2ZnSnSe4 being greatly reduced compared with that of the bulk. Our results are presented in light of the interest in these materials for thermoelectric applications.
Cu2ZnSnSe4 和 Ag2ZnSnSe4 纳米晶通过胶体合成路线合成，然后通过火花等离子烧结 (SPS) 致密化形成具有纳米级晶粒的致密多晶体。采用粉末 X 射线衍射 (XRD)、透射电子显微镜 (TEM) 和电子衍射能谱 (EDS) 对纳米晶进行了表征。研究了纳米结构多晶锡酸盐 Cu2ZnSnSe4 和 Ag2ZnSnSe4 的光学带隙、热稳定性和低温输运性质。Ag2ZnSnSe4 的输运性质在此首次报道，并表明其具有极化子型传导。Cu2ZnSnSe4 为 p 型，而 Ag2ZnSnSe4 为 n 型。还研究了这些材料的热输运性质，与体相比，纳米结构 Cu2ZnSnSe4 的热导率大大降低。我们的结果是基于这些材料在热电应用中的兴趣而提出的。
