Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, Amsterdam, NL-1098 XH, The Netherlands.
Small. 2012 Oct 22;8(20):3185-91. doi: 10.1002/smll.201200477. Epub 2012 Jul 17.
The microscopic origin of the bright nanosecond blue-green photoluminescence (PL), frequently reported for synthesized organically terminated Si quantum dots (Si-QDs), has not been fully resolved, hampering potential applications of this interesting material. Here a comprehensive study of the PL from alkyl-terminated Si-QDs of 2-3 nm size, prepared by wet chemical synthesis is reported. Results obtained on the ensemble and those from the single nano-object level are compared, and they provide conclusive evidence that efficient and tunable emission arises due to radiative recombination of electron-hole pairs confined in the Si-QDs. This understanding paves the way towards applications of chemical synthesis for the development of Si-QDs with tunable sizes and bandgaps.
有机官能团终止的硅量子点（Si-QDs）的合成过程中，常会观察到明亮的纳秒级蓝绿光光致发光（PL）现象，但这种现象的微观起源尚未完全阐明，这对该有趣材料的潜在应用造成了阻碍。本研究全面分析了通过湿化学合成制备的尺寸为 2-3nm 的烷基终止硅量子点的 PL。对整体和单纳米对象水平上的结果进行了比较，结果提供了确凿的证据，表明电子-空穴对在 Si-QDs 中的限制导致了高效且可调谐的辐射复合，从而产生了发射。这种理解为通过化学合成开发具有可调尺寸和能带隙的 Si-QDs 铺平了道路。
