Hot-injection synthesis and characterization of monodispersed ternary Cu2SnSe3 nanocrystals for thermoelectric applications

Cu 2 SnSe 3 (copper tin selenide, CTSe) is one of promising copper-based selenides materials in the use of acousto-optic and photovoltaic fields. In this communication, the CTSe nanocrystals was successfully synthesized by a “hot-injection” protocol in the presence of oleylamine (OLA). Selenium powder dissolved in the mixed solution of OLA and dodecanethiol (DT) were injected into a hot solution of OLA, including copper chloride, tin chloride, at a given reaction temperature. The structure, composition and morphology of the synthesized samples were characterized via using powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and field-emission scanning electron microscopy (SEM). The results revealed that the as-synthesized nanocrystals were single phase polycrystalline, cubic crystal structure, and high monodispersity with an average diameter of 5   nm. The thermoelectric properties of these dense materials compacted from nanocrystals with the temperature range from 300   K to 598   K were studied. The results exhibit a promising figure-of-merit ZT at 598   K, and it demonstrates that the prepared CTSe could potentially be useful for efficient thermoelectric materials.