Organic (Alq3) film, which was coated on a donor plate, was transferred to an organic light emitting diode (OLED) substrate with help of heat generated by a dithering laser beam. The laser beam was diffracted in an acousto-optic modulator (AOM), then focused on the laser-to-heat converting layer of the donor plate; the focused spot followed trajectories guided by rotation of a Galvano-mirror. Three different functional waveforms, sine wave, square wave, and saw tooth wave were applied to the AOM as modulation signal to generate the dithering beam. The fluorescence microscope images of the donor plate showed that the patterns of removed Alq3 film were affected considerably by the modulation waveforms and the phase difference between adjacent dithering beams. Further, the printed images of Alq3 film on the OLED substrate were different from the patterns of removed Alq3 film. Atomic force microscope images indicated that not only direct transfer but also deposition by sublimated vapor of Alq3 contributed to the pattern formation. Printed patterns affected considerably the electricity-to-light conversion characteristics of OLEDs. For uniform transfer, not only the phase relation of dithering beam lines but also adequate waveform were important.
© 2011 Optical Society of Korea
(110.0110) Imaging systems : Imaging systems
(110.6820) Imaging systems : Thermal imaging
(120.2040) Instrumentation, measurement, and metrology : Displays
(120.4640) Instrumentation, measurement, and metrology : Optical instruments
(310.3840) Thin films : Materials and process characterization
Original Manuscript: September 26, 2011
Revised Manuscript: October 28, 2011
Manuscript Accepted: November 7, 2011
Published: December 25, 2011
Kwang-Won Lee, Si-Jin Lee, Jin-Hyuk Kwon, Jong-Hoon Yi, and Lee-Soon Park, "Effect of Laser Beam Trajectory on Donor Plate in Laser Induced Thermal Printing Process," J. Opt. Soc. Korea 15, 362-367 (2011)
References are not available for this paper.