Study of the coherent states in two-dimensional dye aggregates

二维染料聚集体相干态的研究

• 批准号: 04452086
• 负责人: MIYANO Kenjiro
• 金额: $ 4.22万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04452086/
• 关键词: two-dimensional Dye aggregate; Frenkel excitons; disorder; localization; dimensionality; superradiance; 二次元色素集合系; J会合体; H会合体; エキシトン; 蛍光寿命; ポンプ・プローブ法; コヒーレント状態; 双極子相互作用; 四光波混合; 非線形光学

The purpose of this study was to gain the molecular picture of the two-dimensional excitonic states in dye aggregates. For this purpose, we have performed the following experiments :(1) We established the preparation techniques for J- and H-aggregates. For the former, adsorption from solution produced most desirable results whereas, for the latter, Langmuir-Blodgett technique worked best. (2) We made a cryostat equipped with a microscope which enabled us to do spectroscopy from 0.02 mm diameter area in a monolayr. (3) We performed absorption and emission spectroscopy from liquid He temperature to room temperature. (4) We studied harmonic generation from H-aggregate. (5) The fluorescence lifetime was measured with a streak camera. (6) A preliminary study was done using a pump-and-probe method.Our findings are as follows :(1) The spectroscopic data can be perfectly described by the Frenkel exciton picture modified with the static disorder and phonons. (2) The dimensionality does not appear qualitatively in the optical properties. (3) The fluorescence lifetime is extremely fast, which seems to be the manifestation of the large number of coherently excited molecules, a qualitative signature of two-dimensionality. (4) The local-field approximation well describes the second-harmonic generation process in H-aggregate, i.e.the coherency does not affect the harmonic generation.

这项研究的目的是获得染料聚集体中二维激发态状态的分子图。为此，我们进行了以下实验：（1）我们为J-和H-聚集物建立了准备技术。对于前者而言，溶液的吸附产生了最理想的结果，而对于后者，Langmuir-Blodgett技术效果最好。 （2）我们制作了一个配备了显微镜的低温恒温器，使我们能够从单层中直径为0.02 mm的区域进行光谱法。 （3）我们从液体温度到室温进行了吸收和发射光谱。 （4）我们研究了H-聚集的谐波产生。 （5）用条纹摄像头测量荧光寿命。 （6）使用泵和探针方法进行了初步研究。我们的发现如下：（1）光谱数据可以由Frenkel Ickiton图片完美地描述，并用静态障碍和声子修饰。 （2）尺寸在光学性质中没有定性出现。 （3）荧光寿命非常快，这似乎是大量相干分子的表现，这是二维的定性特征。 （4）局部场近似很好地描述了H-聚集的第二次谐波生成过程，即相干性不会影响谐波产生。

项目成果

G.Xu,K.Okuyama,M.Shimomura: "Crystal Structure of H-Aggregate of Azobenzene-containing Amphiphiles,C6AzoC8NBr and C8AzoC10NBr" Mol.Cryst.Liq.Cryst.213. 105-115 (1992)

G.Xu，K.Okuyama，M.Shimomura：“含偶氮苯的两亲物，C6AzoC8NBr 和 C8AzoC10NBr 的 H 聚集体的晶体结构”Mol.Cryst.Liq.Cryst.213。

H.Ui,A.Tomioka,T.Nishiwaki,and K.Miyano: "Local-Field Effects in the Second-Harmonic Generation from Langmuir-Blodgett Monolayers." J.Chem.Phys.101. 6430-6438 (1994)

H.Ui、A.Tomioka、T.Nishiwaki 和 K.Miyano：“Langmuir-Blodgett 单层膜二次谐波产生中的局域场效应”。

M.Kuwata-Gonokami,N.Peyghambarian,et al.: "Exciton Strings in an Organic Charge-transfer Crystal" Nature. 367. 47-48 (1994)

M.Kuwata-Gonokami、N.Peyghambarian 等人：“有机电荷转移晶体中的激子串”自然。

K.Miyano,T.Nishiwaki,A.Tomioka: "A Simple and Accurate Method to Determine the Third-Order Nonlinear Susceptibility of Thin Films" Opt.Commun.91. 501-508 (1992)

K.Miyano、T.Nishiwaki、A.Tomioka：“确定薄膜三阶非线性磁化率的简单而准确的方法”Opt.Commun.91。

下村 政嗣: "分子膜と光情報" 化学工業. 43. 9-13 (1992)

下村正继：“分子薄膜和光学信息”《化学工业》43. 9-13 (1992)。