Laser-Induced Second Harmonic Generation Decay in a Langmuir– Blodgett Film: Arresting by Polyelectrolyte Templating


  • We thank the DST, New Delhi, and JSPS, Tokyo, for financial support and the UPE program of the UGC at the University of Hyderabad for infrastructural support. M. S. C thanks the CSIR, New Delhi, for a senior research fellowship. We thank Mr. Shoichiro Hirakawa for help with some of the experiments. Details of synthesis, LB film fabrication, SHG measurement, electronic spectroscopy, atomic force microscopy, and semiempirical computational modeling are given in the Supporting Information, which is available online from Wiley InterScience or from the author.


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Stabilizing Langmuir–Blodgett (LB) films: Laser irradiation accelerates π dimerization of hemicyanine nonlinear optical chromophores in monolayer LB films and causes degradation of their second harmonic generation capability. The metastability of the film is overcome effectively by polyelectrolyte templating. Nanoscopic characterization (see Figure) of the ultrathin films reveals the impact of the polyelectrolyte.