Preparation of amorphous organic semiconductor thin films with polyperinaphthalene structure on temperature-controlled substrates by excimer laser ablation of 3,4,9,10-perylenetetracarboxylic dianhydride

Amorphous semiconducting organic thin films are prepared on temperature-controlled substrates by excimer laser ablation (ELA) of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) with 308 nm (XeCl) beams. Drastic increase in electric conductivity and decrease in the FT-IR peak intensities related to the side groups of PTCDA monomers are observed for films prepared on substrates above 200 degrees C, Electric conductivity of a film prepared on a substrate at 300 degrees C comes up to 10(-1) S cm(-1). Raman spectroscopic measurement reveals that this film partially contains polyperinaphthalene (PPN) structure. Structural change by increasing substrate temperature and film formation process are discussed. (C) 1998 Elsevier Science B.V.