Laser-induced ion emission during polymer deposition from a flash-frozen water ice matrix

Flash-frozen water solutions of 1% weight PEG (polyethylene glycol) at −50 °C were used as targets at a laser wavelength of 355 nm for polymer deposition with Matrix-Assisted Pulsed Laser Evaporation (MAPLE). For medium laser fluences the transfer of PEG material to the substrate was accompanied by a pronounced ion flow from the matrix target which increases with fluence F as F12. At the highest fluence the ion flow was partly attenuated, presumably due to plume shielding. Below a threshold of 3.5 J/cm2 the PEG was deposited without any measurable ion emission from the target.