Two- and three-photon absorption and frequency upconverted emission of silicon quantum dots
Two- and three-photon absorption and frequency upconverted emission of silicon quantum dots
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DOI：
10.1021/nl800982z
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发表时间：
2008-09-01
期刊：
影响因子：
10.8
通讯作者：
Prasad, Paras N.
中科院分区：
文献类型：
--
作者：
He, Guang S.;Zheng, Qingdong;Prasad, Paras N.
在本次交流中，我们展示了利用波长为778纳米和1335纳米、脉冲持续时间约为160飞秒的飞秒激光脉冲，对氯仿（以及水中）的硅量子点（QDs）进行双光子和三光子激发研究的实验结果。在单光子、双光子和三光子激发下，光致发光光谱分布几乎相同。在单光子和双光子激发下，光致发光发射的时间弛豫测量在0.05纳秒到15微秒的时间范围内呈现出相同的多指数衰减行为，其特征是三个连续的衰减常数：分别为0.75纳秒、300纳秒和5微秒。最后，测量了650 - 900纳米光谱范围内的双光子吸收光谱以及1150 - 1400纳米光谱范围内的三光子吸收光谱。
In this communication, we present the experimental results of two- and three-photon excitation studies on silicon quantum dots (QDs) in chloroform (as well as in water) by using femtosecond laser pulses with wavelengths of 778 and 1335 nm and a pulse duration similar to 160 fs. The photoluminescence spectral distributions are nearly the same upon one-, two-, and three-photon excitation. With one- and two-photon excitation, the temporal relaxation measurements of photoluminescence emission manifest the same multiexponential decay behavior in the time range from 0.05 ns to 15 mu s, characterized by three successive decay constants: 0.75 ns, 300 ns, and 5 mu s, respectively. Finally, the two-photon absorption spectrum in the spectral range of 650-900 nm and the three-photon absorption spectrum in the spectral range of 1150-1400 nm have been measured.