物理化学学报 >> 2009, Vol. 25 >> Issue (11): 2319-2324.doi: 10.3866/PKU.WHXB20091033

研究论文 上一篇    下一篇

两类以芴为中心的有机分子双光子吸收特性

李小静, 李晶, 王传奎   

  1. 山东师范大学物理与电子科学学院, 济南 250014
  • 收稿日期:2009-04-28 修回日期:2009-07-20 发布日期:2009-10-28
  • 通讯作者: 王传奎 E-mail:ckwang@sdnu.edu.cn

Two-Photon Absorption Properties of Two Kinds of Compounds with Fluorene as Centre

LI Xiao-Jing, LI Jing, WANG Chuan-Kui   

  1. College of Physics and Electronics, Shandong Normal University, Jinan 250014, P. R. China
  • Received:2009-04-28 Revised:2009-07-20 Published:2009-10-28
  • Contact: WANG Chuan-Kui E-mail:ckwang@sdnu.edu.cn

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摘要：

在密度泛函理论水平上, 利用响应函数方法研究了实验新合成的两类以芴为π中心的分子(SK-G1和NT-G1)的双光子吸收特性. 计算结果表明, 这两类有机分子都具有较大的单光子和双光子光吸收强度. 在低能量范围内, NT-G1分子的最大单光子吸收峰相对于SK-G1分子来说发生了红移, 且其最大单光子吸收强度是SK-G1分子的两倍. SK-G1和NT-G1分子的最大双光子吸收均发生在第二激发态. NT-G1分子的最大双光子吸收截面约是SK-G1分子的五倍, 并且NT-G1分子存在一个较宽的双光子吸收带. NT-G1分子的较强光学性质与分子内较大的电荷转移过程有关. 采用Onsager模型计算了溶剂分子对溶质分子单光子吸收性质的影响, 理论计算结果和实验测量结果符合得较好.

关键词: 单光子吸收, 双光子吸收, 响应函数方法, 分子光子学

Abstract:

The two-photon absorption properties of two newly synthesized compounds containing fluorene as a π centre (denoted SK-G1 and NT-G1) were calculated using a response function method with density functional theory. Results show that both compounds have large one-photon and two-photon absorption abilities. In the low energy region, the maximum one-photon absorption strength of NT-G1 is twice as much as that of SK-G1 and its maximum absorption is red shifted compared to that for SK-G1. The maximum two-photon absorption cross section of NT-G1 is about five times as large as that of SK-G1 and those are found for the second excited states. Furthermore, NT-G1 has a wider two-photon absorption energy band. The optical properties of the molecules are closely related to their charge transfer processes when they are excited. The solvent effect on their one-photon absorption properties was calculated using the Onsager model. The numerical calculation is found to be in good agreement with experimental measurements.

Key words: One-photon absorption, Two-photon absorption, Response function method, Molecule photonics