• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.132-132
• /
• 2010

In a previous report, we demonstrated that poly (3,4-ethylenedioxythiophene) derived from poly (ionic liquid) (PEDOT:PIL) constitutes a polymeric hole-injecting material capable of improving device lifetime in organic light-emitting diodes (OLEDs).was attributed to aprotection characteristic of PEDOT:PIL for the indium extraction from ITO electrodes, which frequently occurrs in the OLED device with the conventional PEDOT materials. In this study, we report the OLED device lifetime as well asvice efficiencycan be further improved with the modified PEDOT:PIL in whichorganic compounds are incorporated. The deviced performance will be presented in terms of device lifetime and efficiencies.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07b
• /
• pp.1408-1409
• /
• 2005

Organic light-emitting diodes (OLEDs) of metalsemiconductor-metal (MSM) structure have been fabricated by using m-MTDATA [4,4',4"-tris (3-methylphenylphenylamino) triphenylamine] as a hole-injection layer (HIL). The m-MTDATA is shown to be an effective hole-injecting material for the OLED, in that the insertion of m-MTDATA greatly reduces the roughness of anode surface and improves the device performance.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.901-902
• /
• 2003

Three-color organic light-emitting diodes (OLEDs) of metal-semiconductor-metal (MSM) structure have been favricated by using m-MTDATA [4,4',4"-tris (3-methylphenylphenylamino) triphenylamine] as hole injection layer(HIL). The mMTDATA is shown to be an effective hole injecting material, in that the insertion of mMTDATA greatly reduces the roughness of anode surface and improves the device performance. Red, green and blue OLEDs were fabricated, and their color coordinates in CIE chromaticity were found to be (0.600, 0.389), (0.240, 0.525), and (0.171, 0.171), respectively. The luminous efficiencies of the fabricated OLEDs were 1.4 lm/W at 106 $cd/m^{2}$ for red, 1.4 lm/W at 100 $cd/m^{2}$ for green, and 2.0 lm/W at 104 $cd/m^{2}$ for blue.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.33-33
• /
• 2010

Electrical properties of organic light-emitting diodes (OLEDs) were simulated by S.co's program. The OLEDs have stable operating parameters, high luminance, and high efficiency in simulation. The AF stands for amorphous fluoropolymer in simulation, and it was used as a hole-injection layer. In the five structure of OLEDs, an AF layer is sandwiched between the hole-transport layer and the ITO layer to increase the external quantum efficiency. By considering organic light-emitting diodes using an optimal energy gap of AF, it could contribute to the improvement of the efficiency of the device in the simulation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.24 no.9
• /
• pp.750-754
• /
• 2011

In this research, the electric characteristic of organic light-emitting diodes(OLEDs) was studied depending on thickness of amorphous fluoropolymer(Teflon-AF) which is the material of hole injection layer to improve electric characteristic of OLEDs. Sample composition was fabricated in double layer. The basic structure was fabricated by ITO/tris(8-hydroxyquinoline) aluminum (Alq3)/Al and the 2 layer was fabricated by ITO/2,2-Bistrifluoromethyl-4,5-Difluoro-1,3-Dioxole(Teflon-AF)/tris(8-hydro xyquinoline) aluminum (Alq3)/Al. The experiment was carried with variation of thickness of Teflon-AF at 1.0, 2.0, 2.5, 3.0 nm. The result showed when Teflon-AF thickness was 2.5 nm, the electric and optical characteristic were well performed. Moreover, when it was compared with Teflon-AF without materials, it was improved 15.1 times more on luminance, 12.7 times more on luminous efficiency and 12.1 times more on external quantum efficiency. Therefore, OLEDs element with optimum hole injection layer reduced energy barrier and driving voltage, and confirmed that it improved efficiency widely.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.434-435
• /
• 2007

We have demonstrated the characteristics on the variation of hole transporting layer in blue organic light-emitting diodes (OLEDs) using new blue fluorescent emitter. We fabricated two types of hole transporting layer structures that one is 4,4',4"-Tris(N-(2-naphthyl)-N-phenyl-amino)-triphenylamine (2-TNATA) of $600{\AA}$ as a hole injection layer, N,N'-diphenyl-N,N'- (2-napthyl)-(1,1'-phenyl)-4,4'-diamine (NPB) of $200{\AA}$ as a hole transporting layer and another device is NPB of $500{\AA}$ without the 2-TNATA. The devices without the 2-TNATA showed improved characteristic of the luminance and efficiency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07b
• /
• pp.1034-1037
• /
• 2002

In this study, we fabricated red organic electrolu-minescent device with a doping material (DCJTB), and The cell structure used ITO:indium tin oxide $[20{\Omega}]$/CuPc:Hole injection layer 20nm/NPB: Hole transfer layer 40nm/$Alq_3$ (host) + DCJTB(1% or 3%) (guest) Emitting layer 40nm/$Alq_3$ : Electron transfer layer 30nm/Al :Cathode layer 150nm. the luminescent layer consisted of a host material. 8-hydrozyquinoline aluminum $(Alq_3)$, and DCJTB dye as the dopant. a stable red emission (chromaticity coordinates : x=0.64, y=0.36) was obtained in this cell with the luminance range of $100-600cd/m^2$. we study the electrical and optical properties of devices.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.2
• /
• pp.228-235
• /
• 2004

In this thesis, it is designed efficient electrode formation on the organic luminescent device. ITO electrode is treated with $O_2$plasma. In order to inject hole efficiently, there is proposed the shape of anode that inserted plasma polymerized films as buffer layer between anode and organic layer using thiophene monomer. It is realized efficiently electron injection to aluminum due to introduce the quantum well in cathode. In the case of device inserted the buffer layer by using the plasma poiymerization after $O_2$plasma processing for ITO transparent electrode, since it forms the stable interface and reduce the moving speed of hole, the recombination of hole and electronic ate made in the omitting layer. Compared with the devices without buffer layer, the turn-on voltage was lowered by 1.0(V) doc to the introduction of buffer layer Since the quantum well structure is formed in front of cathode to optimize the tunneling effect, there is improved the power efficiency more than two times.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11b
• /
• pp.497-500
• /
• 2001

Due to their better photosensitivity in X-ray, the amorphous selenium based photoreceptor is widely used on the X-ray conversion materials. It was possible to control the charge carrier transport of amorphous selenium by suitably alloying a-Se with other elements(e.g. As, Cl). The charge transport properties of amorphous Selenium is decided on hole which is induced from metal to selenium in metal-selenium junction and which is transferred in a-Se bulk. This phenomenon is resulted of changing electric field owing to increasing of space charge by deep trap of a-Se bulk. In this paper, We dopped the chlorine to compensate deep hole trap and deposited blocking layer using dielectric material to prevent from increasing space charge for injection charge between metal electrode and a-Se layer. We compared space charge and the decreasing of trap density through measuring dark and photo current. 缀Ѐ㘰〻ሀ䝥湥牡氠瑥捨湯汯杹

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.05a
• /
• pp.263-266
• /
• 1999

Electrolunlinescent devices based on conjugated polymer emitting materials have been much attracted possible applications for multicolor flat panel display, since the conjugated polymers have a small band gap emitting obtained at a low driving voltage. In this paper, we fabricated the single layer EL device using poly(3-hexylthiophene) as emitting material Electroluminescence(EL) and I-V-L characteristics of indium-tin-oxide[ITO]P3HT/AI device with a various thickness were investigated. It was demonstrate that the I-V characteristics depend, not the voltage but the electric- field strength, The current is dependent on the electric filed and not on the applied voltage, indicating that the carriers are injected by a tunneling process. In the device, the barrier to hole injection is only 0.5eV and the barrier to electron injection is 1.5eV.