Estimate of the effective conjugation length of polythiophene from its |χ(3)(ω;ω,ω,−ω)| spectrum at excitonic resonance

作     者：S. Kishino Y. Ueno K. Ochiai M. Rikukawa K. Sanui T. Kobayashi H. Kunugita K. Ema 

作者机构：Core Research for Evolutional Science and Technology (CREST) Japan Science and Technology Corporation (JST) 1-4-25 Mejiro Toshima-ku Tokyo 171-0031 Japan 

出 版 物：《Physical Review B》 (Phys. Rev. B Condens. Matter Mater. Phys.)

年 卷 期：1998年第58卷第20期

页      面：R13430(R)-R13430(R)页

核心收录：

学科分类：0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

摘      要：The spectra of the third-order optical nonlinearity, |χ(3)(ω;ω,ω,−ω)|, around excitonic resonance in a spin-coated film and a Langmuir-Blodgett (LB) film of polythiophene derivative, poly(3-[2-((S)-2-methylbutoxy)ethyl]thiophene), were measured using the degenerate four-wave-mixing method. The obtained value of |χ(3)(ω;ω,ω,−ω)| at the excitonic resonance was ∼10−7esu, which was the largest value ever obtained in conjugated polymers. From the absorption spectra and |χ(3)| spectra, the average effective conjugation lengths of the spin-coated film and the LB film were estimated to be approximately 20- and 36-thiophene rings, respectively.