• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2004년도 하계종합학술대회 논문집(2)
• /
• pp.493-496
• /
• 2004

Recently, organic thin films are widely used to the application of organic optoelectronic devices such as OLED, OTFT, organic solar cell, and organic laser, etc. The electrical transport of organic thin film is very important to determine the performance and thus should be analyzed for analysis of operation and design of devices. However, there have been rarely known about the electrical transport of organic thin films. As an example pentacene is known to be a good organic semiconductor to produce the best performance in OTFT at the present. But the performance is varied depending on the position of source/drain contacts and gate surface states and the thickness of thin film. Therefore, it is necessary to investigate the effects of the above-mentioned factors on the electrical properties of pentacene thin film.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2005년도 춘계학술대회 논문집
• /
• pp.216-219
• /
• 2005

In recent, LCD becomes one of the main display devices and expected to have quite good market share during the next couple of years. The demand for low cost and high performance, however, is becoming severe as the competition among other display devices like PDP, OLED increases. To satisfy this demand from market, we need to optimize the parts or modules of the LCD, reduce the number of the assemble and enhance the process for the high brightness and uniformity of the LCD. The LCD consists mainly of LCD panel and Backlight unit(BLU). BLU, which takes big portion of the cost for LCD, consists of light source, light guide panel and many kinds of functional film. Recently light guide panel or film for BLU has micro patterns on its surface and consequently to reduce the number of parts and enhace the brightness and its uniformity. In this study, some methodologies for the fabrication of the master/stamper and molding the light quide panel are introduced for 50um pitch of prizm patterned substrate. Mechanical machining process is adapted and optimized to fabricate micro patterned stamper using the micro cutting tool. Injection molding technology is also developed to obtain uniformly replicated micro patterned products.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
• /
• pp.1103-1107
• /
• 2007

Highly efficient organic electroluminescent devices (OLEDs) based on 4,7- diphenyl-1, 10- phenanthroline (BPhen) as the electron transport layer (ETL), tris (8-hydroxyquinoline) aluminum ($Alq_3$) as the emission layer (EML) and N,$\acute{N}$-bis-[1-naphthy(-N,$\acute{N}$diphenyl-1,1´-biphenyl-4,4´-diamine)] (NPB) as the hole transport layer (HTL) were developed. The typical device structure was glass substrate/ ITO/ NPB/$Alq_3$/ BPhen/ LiF/ Al. Since BPhen possesses a considerable high electron mobility of $5\;{\times}\;10^{-4}\;cm^2\;V^{-1}\;s^{-1}$, devices with BPhen as ETL can realize an extremely high luminous efficiency. By optimizing the thickness of both HTL and ETL, we obtained a highly efficient OLED with a current efficiency of 6.80 cd/A and luminance of $1361\;cd/m^2$ at a current density of $20\;mA/cm^2$. This dramatic improvement in the current efficiency has been explained on the principle of charge balance.

• 반도체디스플레이기술학회지
• /
• 제5권3호
• /
• pp.23-27
• /
• 2006

Recently, Top emission organic light-emitting diode (TEOLED) has been attracted by their potential application for the development of flat panel display (FPD). We have fabricated the high luminance top emission organic-emitting diode (TEOLED) using dual cathode layer and three top emitting structure. These devices were characterized by electroluminescence (EL) and current density-voltage (J-V) measurements. After compared it with Au anode structure, luminance of the device using dual anode was better than using without Al device. Consequently, Al layers are very good candidates for a promising electron-injecting buffer layer for top emission light-emitting diode (TEOLED).

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
• /
• pp.579-581
• /
• 2004

A new DCM derivative containing the phenoxazine moiety (DCPXZ) has been synthesized for use as a red fluorescent dye molecule in organic light-emitting diodes (OLEDs). The photoluminescence and electroluminescence properties of DCPXZ were examined. The maximum photoluminescence of DCPXZ in chloroform solution ($10^{-5}$ mol) was observed at 616 nm. EL devices were fabricated with the structure ITO/PEDOT-PSS/Cu-PC(15nm)/${\alpha}$-NPD(45nm)/$Alq_3$:DCPXZ(30nm)/$Alq_3$(30nm)/LiF(0.5nm)/Al. The maximum EL emission for the 2.0% DCPXZ-doped device was at 608 nm with CIE coordinates (0.57, 0.42). The EL device exhibited a maximum brightness of 15,000 cd/$m^2$ at 19.4 V and a power efficiency of 1.04 lm/W at a luminance of 100 cd/$m^2$.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
• /
• pp.265-268
• /
• 2004

We have developed a highly efficient and stable blue organic electroluminescent device (OLED) based on the blue fluorescent p-bis(p-N,N-diphenyl-aminostyryl)benzene (DSA-Ph) dopant in a morphologically stable high-bandgap host material, 2-methyl-9,10-di(2-naphthyl)anthracene (MADN), which achieved an EL efficiency of 9.7 cd/A and 5.5 lm/W at 20 mA/$cm^2$ and 5.7 V with a Commission Internationale d'Eclairage coordinates of(x = 0.16, y = 0.32). This sky blue device which could also alleviate the problematic current induced quenching at high current achieved a half-decay lifetime ($t_{1\;2}$) of 46,000 h at an initial brightness of 100 cd/$m^2$.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
• /
• pp.980-983
• /
• 2002

We investigated the effect of quinolate metal complex layer as an electron injection layer on the performance of OLEDs and optimized the device efficiency by varying from 0.5 to 10nm thickness of Liq layer. OLED with a structure of indium tin oxide/$\alpha$-napthylphenylbiphenyl(NPB,40nm)/tris-(8-hydroxyquinoline)aluminum(Alq3, 50nm)/Aluminum(150nm) were fabricated in sequence. The device with 1nm Quinolate metal complex layer showed significant enhancement of the device performance.

• 한국반도체및디스플레이장비학회:학술대회논문집
• /
• 한국반도체및디스플레이장비학회 2007년도 춘계학술대회
• /
• pp.238-243
• /
• 2007

최근 FPD에 투명전극으로 사용되는 ITO는 뛰어난 전기적, 광학적 특성을 가지고 있다. 하지만 ITO는 저온공정의 어려움과 ITO의 원료인 In의 수급 불안정 및 스퍼터링 시 음이온 충격에 의한 막 손상으로 인한 저항 증가 등과 같은 것들이 문제점으로 지적되고 있다. 본 실험에서는 ITO 투명전극을 대체하기 위한 물질로 2wt.%의 Al이 도핑된 ZnO 세라믹 타겟을 이용한 RF 마그네트론 스퍼터링 방법으로 상온, $150^{\circ}C,\;225^{\circ}C,\;300^{\circ}C$ 및 다양한 증착압력 하에서 유리기판 위에 AZO 투명전도막을 증착하였다. 박막의 결정성과 입자의 크기 증착조건에 영향을 받았다. AZO 박막의 전기적특성은 기판온도가 고온일수록 향상되었으며, 박막의 두께가 200nm으로 일정할 때 가시광 영역에서의 투과도는 평균 80% 정도였다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
• /
• pp.454-457
• /
• 2008

We report the syntheses, photophysical properties and device performances of solution processible host material for green-phosphorescent OLEDs. The butterfly-shaped new host materials with nonconjugated linkage of carbazole and fluorene moieties have large triple energy band gap around 2.8 eV. All of the EL devices exhibited turn-on voltages in the range of 4.8-5.0 V. GH-4 exhibited the best performance with a maximum current efficiency and power efficiency of 21.1 cd/A and 7.9 lm/W.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
• /
• pp.925-927
• /
• 2008

In order to improve the performance in green phosphorescent OLED devices, Merck has developed novel host and electron blocking materials. The newly developed host materials improve the device lifetime by a factor of 3. The newly developed electron blocking materials having not only electron but also exciton barrier properties increase the efficiency of the device by a factor of 1.4. Comparable results were achieved in phosphorescent red systems with further host materials.