Third-order nonlinear optical properties of π-conjugated polymers with thiophene units and molecular assembly of the polymers
H. Kishida, Nagoya University, Japan
T. Yamamoto, Tokyo Institute of Technology, Japan
Third-order optical nonlinearity in thiophene unit-based conjugated polymers is discussed. Optical nonlinearity is enhanced by improvement of the regioregularity of main chains and reduction of steric repulsion between main chains and side chains. The introduction of charge-transfer character to the electronic states also increases the figure of merit of optical nonlinearity. Moreover, it is explained that the manner of molecular assembly affects the electronic states. Piezochromism in poly(thiophenes) is demonstrated ...