Sung-Kee Kang

A 3.0-in. 308-ppi WVGA AMOLED with a top-emission white OLED and color filter

— A 3.0-in. 308-ppi WVGA top-emission AMOLED display with a white OLED and color filters, driven by LTPS TFTs demonstrating a color gamut of >90% and a Δ(u′,v′) of <0.02 is reported. A white-emission source with a unique device structure was developed using all fluorescent materials and yielded efficiencies of 8.45% and 16 cd/A at 4000 nits with CIE color coordinates of (0.30, 0.32).

54.4: Highly Efficient and Wide Color Gamut White OLED Architecture for Display Application

Highly efficient WOLEDs, with the efficiencies of 19 cd/A, 16 cd/A, and 33 cd/A and CIE color coordinates of (0.25, 0.35), (0.30, 0.32), and (0.30, 0.32) respectively, have been developed. The broad white emitting TE-WOLEDs for high resolution display have been realized by controlling the microcavity between the cathode and anode. 96 % of NTSCx,y ratio was achieved from the TE-WOLED with the optical path control layer (OPCL) and new green color filter (CF).

P-16: Integration of the 4.5″ Active Matrix Organic Light-emitting Display with Organic Transistors

We developed an active matrix organic light-emitting display(OLED) on a glass using two organic thin-film transistors(OTFTs) and a capacitor in a pixel. The OTFTs has bottom contact structure with a unique gate insulator and pentacene for the active layer. The width and length of the switching OTFT is 500 μm and 10 μm respectively and the driving OTFT has 900 μm channel width with the same channel length. The characteristics of the OTFTs were examined by test cells around display area and generated images on the panel. The mobility was 0.3 cm2V−1S−1 and the current on/off ratio was 106. The uniformity and stability were confirmed through still and moving images on the panel. The organic light-emitting layers were fabricated by shadow mask process and color fluorescence materials were used for the emitting layers. The resolution of the panel is 64×RGB×64 in 4.5 inch diagonal and the aperture ratio was 25%.

P‐146: Highly Efficient Top Emitting White OLED Architecture for Micro‐display Applications

Very high current efficiency of 18.4 cd/A (conversion white efficiency 4 cd/A) for a single optical path top emitting WOLED and 15.8 cd/A conversion white efficiency for a multiple optical path top emitting WOLED has been successfully demonstrated. The VCRC (volume color reproduction capability) of these white OLEDs with color filters achieved 106% and 142% of sRGB, respectively.

P-228: Degradation of White Light Emitting OLEDs

We firstly report the degradation analysis of multilayer structured WOLED by using spectroscopic and microscopic analytical methods. Our analytical results demonstrated that the interface between cathode and electron-transporting layer is responsible for the intrinsic long-term degradation of WOLEDs.

Passivation Layers for Organic Thin-film-transistors

Inorganic layers, such as SiOxNy and SiOx deposited using plasma sublimation method, were tested as passivation layer for organic thin-film-transistors (OTFTs). OTFTs with bottom-gate and bottom-contact structure were fabricated using pentacene as organic semiconductor and an organic gate insulator. SiOxNy layer gave little change in characteristics of OTFTs, but SiOx layer degraded the performance of OTFTs severely. Inferior barrier properties related to its lower film density, higher water vapor transmission rate (WVTR) and damage due to process environment of oxygen of SiOx film could explain these results. Polyurea and polyvinyl acetates (PVA) were tested as organic passivation layers also. PVA showed good properties as a buffer layer to reduce the damage come from the vacuum deposition process of upper passivation layers. From these results, a multilayer structure with upper SiOxNy film and lower PVA film is expected to be a superior passivation layer for OTFTs.

Integration of 4.5” active matrix organic light‐emitting display with organic transistors

Abstract We developed a 4.5” 192x64 active matrix organic light‐emitting diode display on a glass using organic thin‐film transistor (OTFT) switching‐arrays with two transistors and a capacitor in each sub‐pixel. The OTFTs has bottom contact structure with a unique gate insulator and pentacene for the active layer. The width and length of the switching OTFT is 800 ? and 10? respectively and the driving OTFT has 1200? channel width with the same channel length. On/off ratio, mobility, on‐current of switching OTFT and on‐current of driving OTFT were 106,0.3∼0.5 cm2/V•sec, order of 10 μA and over 100 μA, respectively. AMOLEDs composed of the OTFT switching arrays and OLEDs made using vacuum deposition method were fabricated and driven to make moving images, successfully.