53.2: Invited Paper: Large‐Area Color‐Patterning Technology for AMOLED

Abstract

In this paper, we describe a novel color patterning method for the fabrication of large area full‐color AMOLEDs. Laser Induced Thermal Imaging (LITI) is a laser addressed thermal patterning technology with unique advantages such as excellent uniformity of transfer film thickness, capability of multilayer stack transfer, high resolution and scalability to large‐Size mother glass. We developed and optimized transfer films, structure of OLED layers, and laser scanning conditions for the patterning of evaporated small molecules. As a result, we achieved excellent LITI device stability which yielded the device life time more than 25,000 hrs at 250 cd/m2 white brightness.

Laser-Induced Forward Transfer of Polymer Light-Emitting Diode Pixels with Increased Charge Injection

“…Small-molecule OLEDs have a number of much better developed pixel deposition methods, most notably vacuum evaporation through a shadow mask 12 and laser-induced thermal imaging (LITI). 13 Highlighting the potential fleixibility of LIFT, tris 8-hydroxyquinoline aluminium (Alq 3 ), a sensitive small molecule organic light-emitting diode (OLED) material, has also been successfully transferred using a thick polymeric DRL. 14 In the previous study, we used the single functional layer diode architecture with a transparent ITO-coated glass anode, the light-emitting MEH-PPV layer, and an aluminium top cathode (ITO/MEH-PPV/Al) to provide a proof of the principle that PLED pixels can indeed be fabricated by LIFT.…”

Laser Patterning Technologies

“…As one of such candidates, direct write techniques with laser system could be very useful for patterning of various materials including polymers or small molecular species. The related methods include matrix-assisted pulsed laser evaporation (MAPLE) (Piqué et al 2002), laser ablative transfer (LAT) (Piqué 2011), radiation-induced sublimation transfer (RIST) (Boroson et al 2005), laser-induced pattern-wise transfer (LIPS) (Hirano et al 2007), laser-induced forward transfer (LIFT) (Kordás et al 2001;Lee et al 2002Lee et al , 2007Wu et al 2001;Tien et al 2001), laser-induced thermal imaging (LITI) (Tolbert et al 1993;Wolk et al 2008;Suh et al 2009;Cho et al 2012a), and so on. Actually, there has been lots of progress on laser patterning process so that we could prepare the highresolution as well as large-area AMOLED panels by using laser-induced imaging technology (e.g., LIPS, LITI).…”

“…But such kinds of cleaning process were hardly applicable because of the concern about device deterioration by secondary impact which may cause concomitant Fig. 31 (a) Photographic image of 3.2 00 WVGA panel displaying a picture (854 Â RGB Â 480, 308 ppi); (b) optical micrograph of subpixels emitting R, G, and B in this panel; and (c) photographic images of panel emitting B, G, R, and W colors (Suh et al 2009) particles. Thus, Cha et al applied mechanically robust polymeric charge transport material as an optical path length control layer (OPCL) which can give an alternative solution to realize "super top-emission" structure although ITO-OPCL approach is also a very good solution (Kashiwabara et al 2004).…”

Thermal buffer materials for enhancement of device performance of organic light emitting diodes fabricated by laser imaging process

“…Indeed, laser imaging process normally causes a temperature increase up to several hundred degrees centigrade during the transfer process of organic materials by thermal stimulation by laser source at light to heat conversion (LTHC) layer (as shown in Fig. 1(a)), although the duration time at the peak temperature is only within a millisecond [16,17]. Hence, the blue common layer (BCL) structure containing the blue layer on top of red and green layers (without using any interlayer inbetween them as Fig.…”