Wang Chunlei, Zhang Hao, Zhang Junhu, Li Minjie, Han Kun, Yang Bai
Key Lab for Supramolecular Structure and Materials, Jilin University, Changchun 130012, People's Republic of China.
J Colloid Interface Sci. 2006 Feb 1;294(1):104-8. doi: 10.1016/j.jcis.2005.06.085. Epub 2005 Aug 19.
CdS nanocrystals were synthesized in 1-octadecene (ODE) solution with oleic acid (OA) as a capping agent. Freshly prepared CdS nanocrystals showed a weak orangelike fluorescence due to defects on the particle surface. After several weeks' storage, the bulk fluorescence of CdS nanocrystals was dramatically enhanced, which gave the nanocrystals a blue or violet appearance. UV and photoluminescence (PL) measurements were employed to investigate this process. It has been found that the oxygen in the air played the most important role. The oxygen atoms could absorb on the surface of particles and a layer of oxide was gradually formed, which effectively passivated the surface of CdS nanocrystals. Interestingly, this oxidative process had no relation to UV illumination.
硫化镉纳米晶体是在以油酸（OA）为封端剂的1-十八烯（ODE）溶液中合成的。新制备的硫化镉纳米晶体由于颗粒表面的缺陷而呈现出微弱的橙色荧光。储存几周后，硫化镉纳米晶体的整体荧光显著增强，使纳米晶体呈现出蓝色或紫色外观。采用紫外和光致发光（PL）测量来研究这一过程。已经发现空气中的氧气起到了最重要的作用。氧原子可以吸附在颗粒表面，逐渐形成一层氧化物，这有效地钝化了硫化镉纳米晶体的表面。有趣的是，这种氧化过程与紫外光照无关。
