Effects of laser wavelength, fluence, and pulse duration on infrared pulsed laser deposition of a conducting polymer

摘要

Thin films of a conducting polymer have been grown by resonant infrared matrix-assisted pulsed-laser evaporation (RIR-MAPLE). Properties of the thin films such as surface morphology and electrical conductivity have been investigated as a function of laser wavelength, fluence, and pulse structure. Using a free-electron laser whose wavelength is continuously tunable throughout the mid-infrared region (2-10 μm), we are able to deposit polymer films from various liquid matrices by resonantly exciting selective vibrational modes of the solvent. An Er:YAG laser operating at 2.94 μm is used to study the effects of different laser pulse durations. In the case of poly(3,4 ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), it is found that only specific excitation wavelengths and pulse durations lead to the deposition of smooth and functional polymer films.