• Bulletin of the Korean Chemical Society
• /
• v.28 no.9
• /
• pp.1588-1590
• /
• 2007

• Proceedings of the Korean Magnestics Society Conference
• /
• 2008.12a
• /
• pp.150.1-150.1
• /
• 2008

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.181-185
• /
• 2006

The flexible 2-inch AMOLED with $176{\times}144$ pixels has been demonstrated using top emission OLED driven by organic thin film transistors (OTFTs). For the development of AMOLED display on plastic substrate, we have developed several integration and unit process technologies. Through the optimization of the process based on plastic substrate, OTFT backplane with 2 transistors and 1 capacitor in a pixel has been fabricated and integrated with top emission OLED. The active addressing by OTFT driving circuit has been achieved and green light with 15 $cd/m^2$ at 15V has been observed.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.781-784
• /
• 2005

We have developed technology to fabricate large-size active matrix organic light-emitting diode (AMOLED) displays with good color purity. Using these innovations, we have developed a 40inch diagonal WXGA AMOLED full color display. Because the TFT circuitry occupies a large portion of the pixel structure, an efficient white emission OLED is essential to integrate the device onto the active matrix backplane. The development of these technologies enables OLED displays to fulfill the requirements for larger size applications such as HDTVs

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.11a
• /
• pp.269-270
• /
• 2005

A hybrid passivation method using parylene and silicon dioxide combination layer for a flexible organic light emitting diode (FOLED) was applied on a polycarbonate substrate. A parylene coating by vapor polymerization method is a highly effective passivation process for the FOLED, and it applies all top surface and the edges of the FOLED device. In order to minimize the permeation of moisture and oxygen from the top surface of the device, an additional layer of silicon dioxide was deposited over the parylene coated layer. It was found that the water vapor transmittance rate (WVTR) of parylene (15 m-in-thickness) / SiO2 (0.3$\mu$m-in-thickness) combination layers deposited on polycarbonate film was decreased under the value of 10-3 g/m2day. The FOLED with the hybrid passivation showed remarkably longer lifetime characteristics in the ambient conditions than the non-passivated FOLED. The lifetime of the passivated FOLED was 400 hours and it was more than ten times over the lifetime of the convectional non-passivated FOLED.

• Journal of the Semiconductor & Display Technology
• /
• v.9 no.4
• /
• pp.1-5
• /
• 2010

The PVA (poly-vinyl alcohol) insulators were spun coated onto ITO coated glass substrates with the capacitors of Glass/ITO/PVA/Al structure. The effects of PVA concentrations (3.0, 4.0 and 5.0 wt%) on the morphology and electrical properties of the films were investigated. As the concentration of PVA increased from 3.0 to 5.0 wt%, the leakage current of device decreased from 17.1 to 0.23 pA. From the AFM measurement, the RMS value decreased with increasing PVA concentration, showing the improvement of insulator film roughness. The capacitances of the films with PVA concentrations of 4.0 and 5.0 wt% were about 28.1 and 24.2 nF, respectively. The lowest leakage current of 1.77 PA was obtained at the film thickness of 117.5 nm for the device with fixed PVA concentration of 5.0 wt%.

• Journal of the Semiconductor & Display Technology
• /
• v.10 no.1
• /
• pp.27-32
• /
• 2011

In this study, we have investigated the power conversion efficiency of organic solar cells utilizing conjugated polymer/fullerene bulk-hetero junction(BHJ) device structures. We have fabricated poly(3-hexylthiophene)(P3HT), poly[2methoxy-5-(3',7'-dimethyloctyl-oxy)-1-4-phenylenevinylene] as an electron donor, [6,6]-phenyl $C_{61}$ butyric acid methylester(PCBM-$C_{61}$)as an electron acceptor, and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS) used as a hole injection layer(HIL), after fabricated active layer, between active layer and metal cathode(Al) deposited LiF interlayer(5 nm). The properties of fabricated organic solar cell(OSC) devices have been analyzed as a function of different thickness. The electrical characteristics of the fabricated devices were investigated by means J-V, fill factor(FF) and power conversion efficiency(PCE). We observed the highest PCEs of 0.628%(MDMO-PPV:PCBM-$C_{61}$) and 2.3%(P3HT:PCBM-$C_{61}$) with LiF inter-layer at the highest thick active layer, which is 1.3times better than the device without LiF inter-layer.

• ETRI Journal
• /
• v.35 no.4
• /
• pp.734-737
• /
• 2013

Nonvolatile ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) memory based on an organic thin-film transistor with inkjet-printed dodecyl-substituted thienylenevinylene-thiophene copolymer (PC12TV12T) as the active layer is developed. The memory window is 4.5 V with a gate voltage sweep of -12.5 V to 12.5 V. The field effect mobility, on/off ratio, and gate leakage current are 0.1 $cm^2/Vs$, $10^5$, and $10^{-10}$ A, respectively. Although the retention behaviors should be improved and optimized, the obtained characteristics are very promising for future flexible electronics.

• 전자공학회논문지 IE
• /
• v.45 no.1
• /
• pp.1-6
• /
• 2008

In this paper, the white organic LED with two-wavelength was fabricated using the NPB of blue emitting material and a series of orange color fluorescent dye(Rubrene) by vacuum evaporation processes. The structure of white OLED was ITO/NPB$(200{\AA})$NPB:Rubrene$(300{\AA})$/BCP$(100{\AA})/Alq_3(100{\AA})/Al(1000{\AA})$ and the doping concentration of Rubrene was 0.75 wt%. We obtained the white OLED with CIE color coordinates were x=0.3327 and y=0.3387, and the maximum EL wavelength of the fabricated white organic light-emitting device was 560 nm at applied voltage of 11 V, which was similar to NTSC white color with CIE color coordinates of x=0.3333 and y=0.3333. The turn-on voltage is 1 V, the light-emitting him-on voltage is 4 V. We were able to obtain an excellent maximum external quantum efficiency of 0.457 % at an applied voltage of 18.5 V and current density of $369mA/cm^2$.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.6 no.2
• /
• pp.95-112
• /
• 1998

For the effective disposal of organic food wastes, we seleted 4 strains of microorganism from 186 microbial candidate via enzyme activity test, salt tolerance, food decomposition rate, stability and safety of strains. The identity of these 4 strains are as follows : Fungi is Rhizopus sp., yeasts are Galactomyces sp., Pichia sp. and Hyphopichia sp., In the 50L fermenter scale, we tested various fermenting factor for the optimization of conditions of food waste decomposition using 4 selected strains. The optimum fomenting conditions were as follows : BIO-CHIP Volume 25-30 L, BIO CHIP size 2.0-6.0mm, air flow 200-280L/min, mixing intensity 2-4rpm, temperature $30-45^{\circ}C$. In these fermenting conditions, the efficiency of decomposition(rate of weight loss of food wastes) were 93%. Also the quality of fermenting output were assayed at the basis of fertilizer, and the results were as good as general compost.