Nanobiophysics Group and MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands.
Beilstein J Nanotechnol. 2011;2:516-24. doi: 10.3762/bjnano.2.56. Epub 2011 Aug 30.
We report a single molecule detection scheme to investigate excitation spectra of single emitters at room temperature. We demonstrate the potential of single emitter photoluminescence excitation spectroscopy by recording excitation spectra of single CdSe nanocrystals over a wide spectral range of 100 nm. The spectra exhibit emission intermittency, characteristic of single emitters. We observe large variations in the spectra close to the band edge, which represent the individual heterogeneity of the observed quantum dots. We also find specific excitation wavelengths for which the single quantum dots analyzed show an increased propensity for a transition to a long-lived dark state. We expect that the additional capability of recording excitation spectra at room temperature from single emitters will enable insights into the photophysics of emitters that so far have remained inaccessible.
我们报告了一种单分子检测方案，用于研究室温下单个发射器的激发光谱。我们通过记录单个 CdSe 纳米晶体在 100nm 宽光谱范围内的激发光谱，展示了单发射器光致发光激发光谱学的潜力。这些光谱表现出发射间歇性，这是单个发射器的特征。我们观察到在带边缘附近的光谱中存在很大的变化，这代表了观察到的量子点的个体异质性。我们还发现了一些特定的激发波长，对于这些波长，分析的单个量子点显示出向长寿命暗态跃迁的倾向增加。我们预计，从单个发射器在室温下记录激发光谱的附加功能将使人们能够深入了解迄今为止无法访问的发射器的光物理。
