SnS壳层厚度对ZnO/SnS核壳结构纳米棒光致发光性能的影响

Influence of SnS Shell on Photoluminescence Properties of ZnO/SnS Core/Shell Nanorods

摘要:

通过简单的水热法制备了ZnO纳米棒，然后成功地在ZnO纳米棒上修饰了一层SnS壳层，形成了ZnO/SnS核壳结构纳米棒。利用X射线衍射、扫描电子显微镜和透射电子显微镜对上述核壳结构进行了表征。结果表明制备的ZnO纳米棒直径在20~200nm，长度达1μm，随着SnS壳层修饰时间的增加壳层厚度逐渐增加。PL分析表明，当SnS壳层厚度很薄时，由于ZnO纳米棒表面态得到了修复，ZnO纳米棒的PL强度得到了很好的提升; 但当SnS壳层厚度达到一定程度后，该核壳结构会形成一种Ⅱ型能带排列，这样该核壳结构的PL强度反而会被降低。

Abstract:

ZnO nanorods were fabricated by a simple hydrothermal method. Then SnS shells were covered onto the ZnO nanorods successfully, forming ZnO/SnS core/shell nanorods. XRD, SEM, and TEM were used to characterize the structure of the core/shell structures. It is indicated that the diameter of ZnO nanorods ranges from 20 to 200nm, while the length reaches to 1μm and the thickness of SnS shell increases with the increasing treatment time. PL spectrum reveals that when the shell is very thin, the increase in photoluminescence intensity is attributed to the modification of surface defect state; when the shell becomes thicker, the formation of a type-Ⅱ band alignment between the core and shell is ascribed to be the factor resulting in the intensity decrease of the photoluminescence properties.