| We find that SnSe, which is a very stable and simple compound consisting of Earth-abundant elements,exhibits an intrinsically ultralowthermal conductivity. Historically, SnSewas ignored by the thermoelectric community. Though SnSe is a well-known semiconductor studied for its potential in solar cells or in phase-change memory alloys,its thermoelectric properties have been only scarcely investigated.By studying single crystals of thermoelectric properties SnSe can lay a solid foundation for the future exploration and application performance thermoelectric materials.Thermoelectric effect is a function of the material has the ability to be able to heat and electrical energy between each other conversion, waste heat can be converted into electricity. SnSe crystal thermoelectric material having excellent thermoelectric properties, may have wide application in the manufacture of thermoelectric devices on. Large-sized single crystals in 2014 SnSe Mercouri G. Kanatzidis by Northwestern University research team first reported. We use Bridgman grown larger size SnSe single crystal, but crystal quality to be further improved. In this paper, the process of solid-phase synthesis and crystal growth process SnSe were studied, and the resulting single crystals were SnSe Characterization section, a preliminary study thermoelectric properties SnSe single crystals. The main content of this paper includes the following aspects:1. Synthesis and crystal growth of SnSeWe use high-temperature solid-phase method by elemental Sn and Se synthesizing SnSe pure phase, and systematic study of the reaction temperature curve and the reaction by the quartz crucible outside and then set a larger diameter quartz tube to solve the reaction occurring during quartz crucible cracking problem, to obtain pure phase SnSe poly crystalline material.Bridgman method were SnSe single crystal growth, the system of reaction SnSe single crystal growth process, to determine the temperature field curve, eventually got SnSe single crystal single crystal for SnSe processing, reserved the nature of the test.2. Thermoelectric Performance of SnSe single crystalBy the Bridgman method for growing a single crystal SnSe pyroelectric properties testing, the thermal expansion coefficient of the test, Seebeck coefficient, electrical resistivity, conductivity and thermal conductivity, owing to SnSe about 800K to a phase change from Pnma to Cmcm, test the results are basically reaches about 800K extremum, such as a direction of thermal conductivity 0.533 W/(m*K) reaches a minimum value at about 550 ℃, the conductivity reached a maximum value at 11.6 S cm-1 about 850K, by analyzing and comparison of results there is a gap on the growth of single crystals with foreign SnSe have grown single crystals of SnSe nature, indicating the growth of single crystals SnSe have more defects, quality SnSe single crystals to be further improved. |
