Synthesis and Characterization of Nanostructured Stannite Cu₂ZnSnSe₄ and Ag₂ZnSnSe₄ for Thermoelectric Applications

Abstract

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.

Engineering Solar Cell Absorbers by Exploring the Band Alignment and Defect Disparity: The Case of Cu‐ and Ag‐Based Kesterite Compounds

“…According to this mechanism, the formation energies of the acceptor defects should also be high and thus the p-type doping should be diffi cult in other Ag S or Ag Se compounds with similar valence band component (Ag 4d and S 3p or Se 4p hybridized states). Interestingly, experiments showed that most of the synthesized Ag 2 S, Ag 2 Se, AgInS 2 , AgInSe 2 , and Ag 2 ZnSnSe 4 samples show intrinsic n-type conductivity and their p-type doping is diffi cult, [81][82][83][84][85][86][87][88][89][90] in agreement with our prediction based on the atomic levels.…”

Green Atmospheric Aqueous Solution Deposition for High Performance Cu2ZnSn(S,Se)4 Thin Film Solar Cells

“…In Figure c, the XRD patterns of CAZTSSe films with x ranging from 0 to 8% could be indexed to a tetragonal kesterite phase (JCPDS No. 026‐0575), which display a preferred orientation along the (112) plane at about 27° . A comparison of the enlarged peak‐shift of (112) lattice plane is shown in Figure d, and it is clear that as x value increased from 0 to 8%, the peak position is shifted toward the lower angle by 0.27° (27.76–27.49°).…”

“…026-0575), which display a preferred orientation along the (112) plane at about 27 . [36,37] A comparison of the enlarged peak-shift of (112) lattice plane is shown in Figure 4d, and it is clear that as x value increased from 0 to 8%, the peak position is shifted toward the lower angle by 0.27 (27.76-27.49 ). These results indicate an expansion of the unit cell volume by the replacement of Cu with Ag.…”

Synthesis, crystal structure and electrical properties of the tetrahedral quaternary chalcogenides CuM2InTe4 (M=Zn, Cd)

“…This freedom and complexity has been exploited for different applications, for example, most recently several quaternary chalcogenides have been shown to be of interest for thermoelectrics applications [5][6][7][8]. Most of this work, however, has focused on a narrow range of compositions, with the kesterite or stannite crystal structures [9,10]. New materials investigations with specific desirable properties is therefore of interest in the search for new thermoelectric materials.…”