Comparison of Water-Soluble CdTe Nanoparticles Synthesized in Air and in Nitrogen

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• 作者：Yuanfang Liu ; Wei Chen ; Alan G. Joly ; Yuqing Wang ; Carey Pope ; Yongbin Zhang ; Jan-Olov Bovin ; Peter Sherwood
• 刊名：Journal of Physical Chemistry B
• 出版年：2006
• 出版时间：August 31, 2006
• 年：2006
• 卷：110
• 期：34
• 页码：16992 - 17000
• 全文大小：293K
• 年卷期：v.110,no.34(August 31, 2006)
• ISSN：1520-5207

文摘

It is commonly believed that high-quality CdTe nanoparticles with strong luminescence can only be preparedunder the protection of an inert gas such as nitrogen or argon. Here, we report the preparation of highlyluminescent CdTe nnaoparticles in air and compare their luminescence properties with CdTe nanoparticlesmade in nitrogen. We find that both water-soluble CdTe nanoparticles made in air and in nitrogen exhibitstrong photoluminescence as well as upconversion luminescence at room temperature. However, differencesdo exist between the particles made in air and those made in nitrogen. In particular, the particles prepared inair display a faster growth rate, grow to larger sizes, and display stronger electron coupling relative to theparticles prepared in nitrogen. X-ray photoelectron spectroscopy analysis indicates that the oxygen content inthe nanoparticles synthesized in air is higher that that in particles synthesized in N₂, likely resulting in ahigher availability of excess free cadmium. Cytotoxicity measurements reveal that the particles made in airappear slightly more toxic, possibly due to the excess of free cadmium.