29.3: A Novel Patterning Method for Full‐Color Organic Light‐Emitting Devices: Laser Induced Thermal Imaging (LITI)

Abstract

We have developed a novel color patterning method for the fabrication of large format full‐color OLEDs. Laser Induced Thermal Imaging (LITI) is a laser addressed high resolution thermal patterning process with unique advantages such as excellent transfer film thickness uniformity, multilayer stack transfer ability, and scalability to large‐size mother glass. LITI patterning of small molecule materials produces OLEDs that are comparable in performance to conventional evaporated devices. Using the technology, we fabricated 2.2″ full color active matrix OLEDs.

Effect of Laser Beam Trajectory on Donor Plate in Laser Induced Thermal Printing Process

“…There are several laser methods for OLED fabrication, and among these, laser thermal printing [1][2][3][4][5][6] and laser sublimation [7,8] are the main methods. A laser thermal printing method, which was originally developed for fabrication of the color filters for the LCD panel, was suggested as an alternative method of OLED fabrication [9].…”

“…A laser thermal printing method, which was originally developed for fabrication of the color filters for the LCD panel, was suggested as an alternative method of OLED fabrication [9]. In view of mass productivity, high resolution, multi-layer stacking, and scalability to large size mother glass, the laser method has potential for competing technology [1,3]. In previous studies of the laser thermal printing method, dithering of a laser Effect of Laser Beam Trajectory on Donor Plate in Laser Induced … -Kwangwon Lee et al Trajectories of dithered laser beam recorded on a photographic sheet when sine wave, square wave, and saw tooth waves were applied to the acousto-optic modulator.…”

“…beam was used for OLED panel fabrication [1,3,4]. J. Kwon et al suggested sine, saw tooth, and trapezoidal waveforms for clean patterning because a Gaussian waveform has highest energy at the center of the beam [3].…”

“…J. Kwon et al suggested sine, saw tooth, and trapezoidal waveforms for clean patterning because a Gaussian waveform has highest energy at the center of the beam [3]. However, the effects of dithering waveforms on the printed patterns and analysis of donor film after transfer have not been investigated yet.…”

Laser Beam Shaping Using Hollow Optical Fiber and Its Application in Laser Induced Thermal Printing

“…The irradiated laser energy is converted to heat in the heat absorption layer of the donor film. It is known that the laser beam shape which has more energy at both sides of the beam track is desirable for clean and sharp patterning [12]. To get the profile, the direction of the laser beam is dithered in high frequency by an AOM transversely to the beam scanning direction.…”