Solvothermal Synthesis And Characteristic Of Tin Sulfide And Tin Selenide Nanocrystals

In recent years, semiconductor nanomaterials is one of the most active areas due to their distinguished optical and electronic properties that are different from those of their bulk counterparts. IV-VI metal chalcogenide (S or Se) compounds are important narrow-gap semiconductor materials and have been widely used in diverse areas. In this dissertation, solvothermal method was employed to the preparation of novel morphological SnS and SnSe (SnSe₂), such as microtubes, nanoribbons and nanoflakes. The formation mechanisms of different morphologies are analyzed. The as-obtained products were characterized by X-ray diffractometer (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), energy dispersion spectrum (EDS) and ultraviolet -visible (UV) spectrum. The main results are as follows:SnS nanoribbons with widths of 50³00 nm and lengths up to 6 μm have been prepared using Na₂S as S source on a large scale under ethylene glycol solvothermal conditions. In addition, there is a small quantity of SnS nanoright-angles composed of two nanoribbons in the products. TEM image reveals that the nanoribbon was single crystalline and grew along the [001] direction. Ethylene glycol is important for the formation of SnS nanoribbons.SnS submicrometer-sized tubes have been prepared with thiourea as S source by "In situ Polymer Template-Assisted Growth" technique. The inner diameters and length of the microtubes are 0.4⁰.8 μm and over ten micrometers, respectively. Polyacrylamide gel is used as structure directing reagent in the reaction.SnSe₂ and SnSe nanoflakes have been synthesized via an ethylenediamine-assisted glycol solvothermal route with Na₂SeO₃ or Se powder as Se sources. XRD analysis reveales that the crystal structure of the products is hexagonal SnSe₂ phase and orthorhombic SnSe phase, respectively. The effects of the synthetic...