Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA.
J Am Chem Soc. 2012 Oct 3;134(39):16175-7. doi: 10.1021/ja307996b. Epub 2012 Sep 20.
Chemical reductants of sub-conduction-band potentials are demonstrated to induce large photoluminescence enhancement in colloidal ZnSe-based nanocrystals. The photoluminescence quantum yield of colloidal Mn(2+)-doped ZnSe nanocrystals has been improved from 14% to 80% simply by addition of an outer-sphere reductant. Up to 48-fold redox brightening is observed for nanocrystals with lower starting quantum yields. These increases are quickly reversed upon exposure to air and are temporary even under anaerobic conditions. This redox brightening process offers a new and systematic approach to understanding redox-active surface "trap states" and their contributions to the physical properties of colloidal semiconductor nanocrystals.
研究表明，亚导带电位的化学还原剂能够在胶体 ZnSe 基纳米晶体中诱导出较大的光致发光增强。通过添加外部还原剂，胶体 Mn(2+)-掺杂的 ZnSe 纳米晶体的光致发光量子产率从 14%提高到 80%。对于初始量子产率较低的纳米晶体，观察到高达 48 倍的氧化还原增亮。这些增加在暴露于空气中时会迅速逆转，即使在无氧条件下也是暂时的。这种氧化还原增亮过程为理解氧化还原活性表面“陷阱态”及其对胶体半导体纳米晶体物理性质的贡献提供了一种新的、系统的方法。
