Laser printing of a semiconducting oligomer as active layer in organic thin film transistors: Impact of a protecting triazene layer

摘要

Organic thin-film transistor (OTFT) devices were achieved using the laser-induced forward transfer technique. As p-type organic semiconductor, distyryl-quaterthiophene (DS4T) was vacuum-deposited on a donor sub strate and transferred with picosecond laser pulses on Si/SiO_2-based receiver substrates to form an organic active layer. To avoid laser damage of the organic thin film, a UV-sensitive aryltriazene polymer as a sacri ficial layer was used. The polymer layer, deposited on the donor substrate prior to the organic layer depo sition, has high absorption at the laser wavelength and does not contaminate the printed pixels. The DS4T pixels printed on receiver substrates have well defined morphological properties as shown by atomic force microscopy and scanning electronic microscopy. OTFT devices were characterized in top- and bottom-contact configurations using thermally evaporated gold lines as source-drain electrodes. DS4T pixels printed as active layer for charge transport not only issue mobility values comparable to DS4T layers prepared by vacuum evap oration but also a relative electrical stability over time.