CuInS_2纳米晶的制备和发光性质

Synthesis and Luminescence Properties of CuInS_2 Nanocrystals

以十二硫醇为溶剂,通过选择合适的金属源制备了各种尺寸的CuInS2量子点。观察到随着粒子的尺寸减小,其吸收和发光光谱明显蓝移,存在明显的量子尺寸效应。通过在CuInS2纳米晶表面包覆ZnS壳层,发现随着壳层厚度增加,其发光量子效率明显提高,最大达到了48%;继续增加壳层厚度,其发光量子效率反而降低。进一步测量它们的荧光寿命,发现包覆ZnS壳层后的CuInS2纳米晶的荧光寿命明显增加,证实表面包覆明显减少其表面的无辐射复合中心,提高了其发光效率。进一步制备了CuInS2/ZnS核壳量子点发光二极管,并对其电致发光性质进行了研究。

CuInS2 nanocrystals were prepared by heating inorganic metal salt and dodecanethiol.It was found that absorption edge and photoluminescence peak shifted to shorter wavelength with decreasing the nanocrystal size due to quantum size effect.The overgrowth of as-prepared nanocrystals with a few monolayers of ZnS shell improved the photoluminescence quantum efficiency up to 48%.Further photoluminescence decays of CuInS2 nanocrystals were measured at room temperature.CuInS2/ZnS core/shell nanocrystals exhibited a longer photoluminescence lifetime,compared with the naked CuInS2 nanocrystals.This is because the surface coating of the ZnS shell passiviated the defects on the surface of CuInS2 nanocrystals and improved the photoluminescence quantum yield.Finally,CuInS2/ZnS core/shell quantum dot light emitting diodes were fabricated and their electroluminescence properties were studied.