Moon Hyo Kang

Ultrathin Si Thin-Film Transistor on Glass

We have studied the fabrication of ultrathin single-crystalline-silicon thin-film transistors (TFTs) on glass. The single-crystalline Si layer was transferred to glass by hydrogen implantation and anodic bonding. The thickness of the silicon-on-glass (SiOG) was controlled down to 10 nm by dry etching. The p-channel SiOG TFTs with 10-nm-thick Si exhibited the field-effect mobility of 134.9 cm2/Vmiddots, threshold voltage of -1.5 V, and gate voltage swing of 0.13 V/dec. The TFTs were found to be stable against gate bias stress of +30 or -30 V.

43.3: Power Efficient AMOLED Display with Novel Four Sub-Pixel Architecture and Driving Scheme

We present a novel all-phosphorescent AMOLED pixel architecture with a red, green, light blue and deep blue sub-pixel design. The highly efficient light blue reduces power consumption by 33% compared to an equivalent conventional RGB display using a fluorescent blue sub-pixel. Furthermore, by using a light and deep blue sub-pixel layout, the lifetime of the display will be significantly increased due to the reduced on-time required for the deep blue sub-pixel. Here we demonstrate this new design in a 2.5-inch AMOLED panel.

30.3: Highly Flexible Low Power Consumption AMOLED Displays on Ultra-Thin Stainless Steel Substrates

We present results demonstrating that low power consumption phosphorescent AMOLED displays can be fabricated on ultra-thin (25 μm) stainless steel substrates, combining an amorphous silicon backplane with a top emission phosphorescent OLED frontplane. Preliminary results show the performance of amorphous silicon backplanes adequate to drive AMOLED displays, and flexibility results on these backplanes show that they operate when conformed to a tight diameter of only 5 mm.

9.1: A Stable Full-Color AMOLED Display Using a-Si:H TFTs and White PHOLED

We developed a stable 2.2 inch, full-color AMOLED display using color filter on a-Si:H TFT backplane and a highly efficient phosphorescent white OLED. It is found that the lifetime of the a-Si:H TFT backplane is over 70,000 hrs at the full white brightness of 300 cd/m2.

24.1: A 2 Inch a-Si:H TFT-LCD with Backlight Control TFT Sensors

We have developed a 2.0 inch a-Si:H TFT-LCD with the photosensors for detecting the brightness of backlight and outdoor daylight. Two kinds of sensors were embedded in the TFT backplane with a-Si:H TFTs with bottom gate and top gate structures. A pixel has a switching TFT and a TFT sensor in addition to the capacitance. The TFT sensor exhibited the photo-current of ∼10−9 A and dark current of ∼10−12 A in the operation region of backlight. The dynamic range is 60 dB which is high enough to sense the brightness of the backlight. The output signal saturates at ∼ 20000 Lux in the present work but it can be increased by decreasing the TFT size.

46.4: Distinguished Student Paper: A 2-Inch a-Si:H TFT-LCD with an Embedded Sensor

We developed a 2 inch, QCIF (160×128, black and white), amorphous silicon thin-film transistor liquid-crystal display with an embedded sensor on glass. A pixel is divided into LCD and sensor, in which the size of sensor is optimized to have the linear relationship between the output signal voltage and signal integration time. A very thin top glass was used to make a TFT-LCD. A metal mask is put on the LCD with a top glass of 0.1 mm to improve the contrast of the image.

P-146: Fluorene-Based Deep Blue Polymer Light-Emitting Diodes

We developed the new polymers, SKB1 and SKB2, exhibiting deep-blue emission (CIE: x=0.145–0.148, y=0.093–0.135). The device using SKB1 demonstrated the current efficiency of 3.11 cd/A at 6.6V with 3,251 cd/m2, and then the CIE coordinate of the emission was x=0.147 and y=0.123. The SKB2 device showed the current efficiency of 3.70 cd/A at 6.6V with 2,930 cd/m2, and then the CIE coordinate of the emission was x=0.148 and y=0.135.