title: Large optical nonlinearity induced by singlet fission in pentacene films.
abstract: By creating two triplet excitons from one photo-excited singlet exciton, singlet fission in organic semiconductors has drawn tremendous attention for its potential applications in boosting the efficiency of solar conversion. Here, we show that this carrier-multiplication effect can also be used to dramatically improve the nonlinear optical response in organic materials. We have observed large optical nonlinearity with a magnitude of χ((3)) up to 10(-9) esu in pentacene films, which is further shown to be a result of singlet fission by monitoring the temporal dynamics. The potential application of such efficient nonlinear optical response has been demonstrated with a singlet-fission-induced polarization rotation.
authors.affiliation: National Laboratory of Solid State Microstructures, School of Physics & College of Engineering and Applied Sciences, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China).
authors.forename: Yunlong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: National Laboratory of Solid State Microstructures, School of Physics & College of Engineering and Applied Sciences, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China). cfzhang@nju.edu.cn.
authors.forename: Chunfeng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: National Laboratory of Solid State Microstructures, School of Physics & College of Engineering and Applied Sciences, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China).
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.affiliation: National Laboratory of Solid State Microstructures, School of Physics & College of Engineering and Applied Sciences, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China).
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.affiliation: New and Renewable Energy of Beijing Key Laboratory, School of Renewable Energy, North China Electric Power University, Beijing 102206 (China).
authors.forename: Zhanao
authors.initials: Z
authors.lastname: Tan
authors.affiliation: National Laboratory of Solid State Microstructures, School of Physics & College of Engineering and Applied Sciences, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China).
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Wang
authors.affiliation: National Laboratory of Solid State Microstructures, School of Physics & College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093 (China). mxiao@uark.edu.|Department of Physics, University of Arkansas, Fayetteville, AR 72701 (USA). mxiao@uark.edu.
authors.forename: Min
authors.initials: M
authors.lastname: Xiao
keywords: nonlinear optics; pentacene; singlet fission; time-resolved spectroscopy