Picosecond laser patterning of PEDOT:PSS thin films

• Published in: Synthetic metals Vol. 161; no. 5; pp. 431 - 439
• Main Authors: Semaltianos, N.G., Koidis, C., Pitsalidis, C., Karagiannidis, P., Logothetidis, S., Perrie, W., Liu, D., Edwardson, S.P., Fearon, E., Potter, R.J., Dearden, G., Watkins, K.G.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-03-2011; Elsevier
• Subjects: Ablation; Applied sciences; Charge; Conjugation; Exact sciences and technology; Irradiation; Laser patterning; Lasers; Machinery and processing; Miscellaneous; Patterning; PEDOT:PSS; Plastics; Polymer industry, paints, wood; Position (location); Raman spectroscopy; Spectroscopic Ellipsometry; Spin coating; Technology of polymers; Thin films; Spectroscopic Ellipsometry; Laser patterning; Raman spectroscopy; PEDOT:PSS; Ultrathin films; Patterning; Threshold energy; Experimental study; Conducting polymers; Picosecond; Thiophene derivative polymer; Ethylenedioxythiophene polymer; Pulsed laser; Styrenesulfonate polymer; Doped polymer; Laser ablation technique; Mechanism of action
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/j.synthmet.2010.12.022

Picosecond pulsed laser (10.4
ps, 1064
nm, 5 and 50
kHz) patterning studies were performed, of PEDOT:PSS thin films of varying thickness deposited by spin coating on glass substrates, by ablating the films or by changing locally by laser irradiation the optical and electrical properties of the polymer. From a detailed observation of the morphology of single pulse ablated holes on the surfaces of the films, in combination with simple calculations, it is concluded that photomechanical ablation is the likely ablation mechanism of the films. The single pulse ablation thresholds were measured equal to 0.13–0.18
J/cm
2 for films with thicknesses in the region of ∼100–600
nm. The implications on ablation line patterning of the films using different fluences, scanning speeds and pulse repetition rates, were investigated systematically. Laser irradiation of the films before ablation induces a metal–insulator transition of the polymer because of the formation of charge localization due to a possible creation of molecular disorder in the polymer and shortening of its conjugation length.