• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.21 no.6
• /
• pp.562-568
• /
• 2008

In this paper, the hole injection layer(HIL) materials have been synthesized and analyzed. Their HOMO levels are $4.93{\sim}5.22\;eV$, and their energy band gaps are $2.74{\sim}3.19\;eV$. Their glass transition temperatures($T_g$) are all above $114^{\circ}C$, which implies that they are highly thermal-stable. The green OLED devices with a structure of ITO(150 nm)/NEW_HIL(50 nm)/NPB(30 nm)/$Alq_3$(50 nm)/Al:Li(100 nm) were fabricated and tested, incorporating these newly synthesized HIL materials. According to the test results of OLED devices, the I-V-L performances of these devices increase in the following sequence: ELM307 > ELM200 > ELM321 > ELM327 > ELM325. In addition, the OLED device with ELM307 as a HIL has the highest brightness and efficiency at the same driving voltage. These experimental results have shown that ELM307 can be used as one of the most promising candidates for HIL materials.

• Electronics and Telecommunications Trends
• /
• v.24 no.6
• /
• pp.22-31
• /
• 2009

전 세계는 온실가스의 배출을 줄이기 위한 방안의 하나로 전 에너지 소비의 약 20%를 차지하고 있는 조명의 고효율화를 위한 노력을 다각적으로 벌이고 있으며, 그러한 노력의 일환으로 지난 100년간 사용되어온 백열등이 낮은 효율로 인하여 사용규제 논의의 대상이 되고 있다. 반면, 효율은 백열등의 7~8배인 형광등은 높은 효율에도 불구하고 수은과 납이 함유되어 중금속 사용규제(RoHs, WEEE)로 인하여 그 사용이 규제될 계획이다. 따라서, 백열등과 형광등의 빈자리를 채울 수 있는 친환경 차세대 조명에 대한 수요가 확대되고 있어 LED, OLED와 같은 반도체 조명에 대한 개발이 확대되고 있다. 본 기고서에서는 차세대 조명 중에서 OLED 기술을 기반으로 한 OLED 조명 기술과 선진국 및 선진산업체의 개발 동향을 소개하고자 한다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.281-284
• /
• 2004

Photo-induced memory effect of an organic light-emitting diode(OLED) composed of a hydrazone-derivative(DBAH) dispersed in bis-phenol-A type polycarbonate polymer(PCA) in the presence of thio-Michler's ketone, was investigated by the measuring of the current density and luminance at the various conditions. After the light exposure, the current of the OLED was decreased approximately one order, and the luminance of the OLED also decresed. This memory effct was erasable by heating the OLED to the temperature higher than the glass transition temperature(Tg). As shown in this result, we found the memory effect was erased by heating and returned to its original state in the hole injecting layer(HIL) of the OLED. A series of these phenomena was suggested the possibility of the application to the imaging plate.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.1689-1691
• /
• 2006

DuPont Displays has developed a new solution printing fabrication process for OLED displays, using small molecule OLED materials. The new manufacturing process is more cost-effective and scalable than evaporation of materials through physical masks, and addresses issues associated with ink jet printing. A new material (DB) has been developed for use as a hole-injection layer in OLEDs.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.466-469
• /
• 2009

The life time of AMOLED displays has been dependent on OLED materials up to this point. In particular, image sticking (burn-in) has been one of the most critical issues for AMOLEDs. This paper proposes image sticking compensation AMOLED pixel circuits to address the problem without requiring process or material improvements to the OLED itself. We verified the performance of those circuits by simulation and actual panel implementation.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.499-502
• /
• 2008

Effects of a dielectric capping layer on the luminous characteristics of top emitting organic light emitting diodes (TOLEDs) have been analyzed using a classical electromagnetic theory. Special attention was given to the influence of the cavity length on the effectiveness of the capping layer. The luminance characteristics of the TOLEDs influenced by the combined effects of the cavity length and the capping layer thickness. Furthermore, these combined effects also modify the emission spectrum and pattern of the TOLEDs, which result in the improvement of total luminance of the device, but no significant change in the device out-coupling efficiency.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.276-279
• /
• 2008

Air stable n-type organic field effect transistors (OFETs) based on CB60B are realized using a perfluoropolymer as the gate dielectric layer. The devices showed the field-effect mobility of $0.05\;cm^2P/V\;s$ in ambient air. Replacing the gate dielectric material by $SiO_2$ resulted in no transistor action in ambient air. Perfluorinated gate dielectric layer reduces interface traps significantly for the n-type semiconductor even in ambient air.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.1059-1062
• /
• 2006

We report synthesis and properties of new phenothiazyl polymer derivatives, Poly(10-octyl-10Hphenothiazine-3,7-diyl)(POP), Poly(2',3',6',7'-tertrakis-octyloxy-9-spirobifluorene-2,7-diyl) (PTOSF), and their random copolymers, Poly(10-octylphenothiazine-co-2',3',6',7'-tertrakis-octyloxy-9-spirobifluorene) (POTOSF). PL emission of POP, PTOSF and POTOSF copolymer were found to be 480, 434 and 484nm, respectively. EL emission peak of double-layer EL device of POTOSF was at 494nm (bluish green).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.26 no.7
• /
• pp.539-544
• /
• 2013

To study the encapsulation method for heat dissipation of high brightness organic light emitting diode (OLED), red emitting OLED of ITO (150 nm) / 2-TNATA (50 nm) / NPB (30 nm) / $Alq_3$ : 1 vol.% Rubrene (30 nm) / $Alq_3$ (30 nm) / LiF (0.7 nm) / Al (200 nm) structure was fabricated, which on $Alq_3$ (150 nm) / LiF (150 nm) as buffer layer and Al as protective layer was deposited to protect the damage of OLED, and subsequently it was encapsulated using attaching film and metal sheet. The current density, luminance and power efficiency was improved according to thickness of Al protective layer. The emission spectrum and the Commission International de L'Eclairage (CIE) coordinate did not have any effects on encapsulation process using attaching film and metal sheet The lifetime of encapsulated OLED using attaching film and metal sheet was 307 hours in 1,200 nm Al thickness, which was increased according to thickness of Al protective layer, and was improved 7% compared with 287 hours, lifetime of encapsulated OLED using attaching film and flat glass. As a result, it showed the improved current density, luminance, power efficiency and the long lifetime, because the encapsulation method using attaching film and metal sheet could radiate the heat on OLED effectively.

• Journal of the Korean institute of surface engineering
• /
• v.43 no.6
• /
• pp.272-277
• /
• 2010

We investigated the life time characteristics of OLED device with aluminium oxide ($AlO_x$) passivation film on glass substrate and polyethylene terephthalate (PET) substrate by RF magnetron sputtering for the transparent barrier film applied to flexible OLED device. Basic buffer layer was determined as $Alq_3$(500 nm)-LiF(300 nm)-Al(1200 nm), and the most suitable aluminium oxide ($AlO_x$) film have been formed when the partial volume ratio of oxygen was 20% and the sputtering power was 100 watt and the minimum thickness of buffer was $2\;{\mu}m$. $AlO_x$/epoxy hybrid film was also used as a effective passivation layer for the purpose of improving life time characteristics of OLED devices with the glass substrate and the plastic substrate. Besides, the simultaneous deposition of $AlO_x$/epoxy film on back side of PET could result in better improvement of life time.