Photoelectric generation and second-order nonlinear optical characters of the dichromophore dye molecules

The use of the Langmuir-Blodgett (LB) technique enables centrosymmetric molecules to exhibit strong second-harmonic generation. Upon excitation of the dyes incorporated into LB films deposited on an ITO electrode, steady cathodic photocurrent was obtained. The observed quantum yield of the photocurrent strongly depends on the applied electrode potential, pH of the electrolyte, chemical structure of the dye congeners and the applied electrode potential.