中国物理B ›› 2001, Vol. 10 ›› Issue (13): 54-58.
崔一平1, 汪昕2, 张宇2, 邓慧华2, 沈耀春2, 陆祖宏2
Wang Xin (汪昕)a, Zhang Yü (张宇)a, Deng Hui-hua (邓慧华)a, Shen Yao-chun (沈耀春)a, Lu Zu-hong (陆祖宏)a, Cui Yi-ping (崔一平)b
摘要: Hyper-Rayleigh Scattering (HRS) technique was used to study the second-order nonlinear optical (NLO) responses of aqueous titanium dioxide (TiO2) nanoparticles of 10nm in size, and two nanoparticles-dye composites prepared by adding rhodamine B (Rh610) or the organic tosylate salt of dimethylaminostilbazolium (DAST). Results showed that the "per particle" first hyperpolarizability β for TiO2 nanoparticles is very large, in the range of 1026 esu. With adding Rh610 and DAST, the HRS signals of the composites were further enhanced. And in TiO2/Rh610 composite the enhancement was obviously greater than that of TiO2/DAST composite. It has proved that non-centrosymmetry of the nanocrystal/solution interface contributes mainly to its large "per particle" β, overwhelming the nanocrystal core. So the interactions between nanoparticles surfaces and adsorbed dyes were very important for their second-order NLO responses. HRS technique provides a useful new NLO method to characterize the surface structures and microenvironment of nanoscale materials.
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