Zhong Xinhua, Han Mingyong, Dong Zhili, White Timothy J, Knoll Wolfgang
Department of Materials Science, National University of Singapore, Singapore.
J Am Chem Soc. 2003 Jul 16;125(28):8589-94. doi: 10.1021/ja035096m.
High-quality Zn(x)Cd(1-x)Se nanocrystals have been successfully prepared at high temperature by incorporating stoichiometric amounts of Zn and Se into pre-prepared CdSe nanocrystals. With increasing Zn content, a composition-tunable emission across most of the visible spectrum has been demonstrated by a systematic blue-shift in emission wavelength. The photoluminescence (PL) properties for the obtained Zn(x)Cd(1-x)Se nanocrystals (PL efficiency of 70-85%, fwhm = 22-30 nm) are comparable to those for the best reported CdSe-based QDs. In particular, they also have good PL properties in the blue spectral range. Moreover, the alloy nanocrystals can retain their high luminescence (PL efficiency of over 40%) when dispersed in aqueous solutions and maintain a symmetric peak shape and spectral position under rigorous experimental conditions. A rapid alloying process was observed at a temperature higher than "alloying point". The mechanism of the high luminescence efficiency and stability of Zn(x)Cd(1-x)Se nanocrystals is explored.
通过将化学计量比的锌和硒掺入预先制备的硒化镉纳米晶体中，已在高温下成功制备出高质量的Zn(x)Cd(1-x)Se纳米晶体。随着锌含量的增加，通过发射波长的系统性蓝移，已证明在大部分可见光谱范围内可实现成分可调谐发射。所获得的Zn(x)Cd(1-x)Se纳米晶体的光致发光（PL）特性（PL效率为70 - 85%，半高宽 = 22 - 30 nm）与报道的最佳硒化镉基量子点相当。特别是，它们在蓝光光谱范围内也具有良好的PL特性。此外，当分散在水溶液中时，合金纳米晶体可以保持其高发光率（PL效率超过40%），并在严格的实验条件下保持对称的峰形和光谱位置。在高于“合金化点”的温度下观察到了快速合金化过程。对Zn(x)Cd(1-x)Se纳米晶体高发光效率和稳定性的机制进行了探索。
