Two-Photon Absorption Spectrum of a Single Crystal Cyanine-like Dye
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- 作者：Honghua Hu ; Dmitry A. Fishman ; Andrey O. Gerasov ; Olga V. Przhonska ; Scott Webster ; Lazaro A. Padilha ; Davorin Peceli ; Mykola Shandura ; Yuriy P. Kovtun ; Alexey D. Kachkovski ; Iffat H. Nayyar ; Art毛m E. Masunov ; Paul Tongwa ; Tatiana V. Timofeeva ; David J. Hagan ; Eric W. Van Stryland
- 刊名：The Journal of Physical Chemistry Letters
- 出版年：2012
- 出版时间：May 3, 2012
- 年：2012
- 卷：3
- 期：9
- 页码：1222-1228
- 全文大小：405K
- 年卷期：v.3,no.9(May 3, 2012)
- ISSN：1948-7185
文摘
The two-photon absorption (2PA) spectrum of an organic single crystal is reported. The crystal is grown by self-nucleation of a subsaturated hot solution of acetonitrile, and is composed of an asymmetrical donor-蟺-acceptor cyanine-like dye molecule. To our knowledge, this is the first report of the 2PA spectrum of single crystals made from a cyanine-like dye. The linear and nonlinear properties of the single crystalline material are investigated and compared with the molecular properties of a toluene solution of its monomeric form. The maximum polarization-dependent 2PA coefficient of the single crystal is 52 卤 9 cm/GW, which is more than twice as large as that for the inorganic semiconductor CdTe with a similar absorption edge. The optical properties, linear and nonlinear, are strongly dependent upon incident polarization due to anisotropic molecular packing. X-ray diffraction analysis shows 蟺-stacking dimers formation in the crystal, similar to H-aggregates. Quantum chemical calculations demonstrate that this dimerization leads to the splitting of the energy bands and the appearance of new red-shifted 2PA bands when compared to the solution of monomers. This trend is opposite to the blue shift in the linear absorption spectra upon H-aggregation.