• 반도체디스플레이기술학회지
• /
• 제16권1호
• /
• pp.1-5
• /
• 2017

Encapsulation of organic based devices is essential issue due to easy deterioration of organic material by water vapor. Thin layer of encapsulation film is required to preserve transparency yet protecting materials in it. Atomic layer deposition(ALD) is a promising solution because of its low temperature deposition and quality of the deposited film. $Al_2O_3$ or $Al_2O_3/TiO_2/Al_2O_3$ multilayer film has shown excellent environmental protection characteristics despite of thin thicknesses of the films. $Al_2O_3/TiO_2/Al_2O_3$ multilayer and 1.5 dyad layer of $Al_2O_3/polymer/Al_2O_3$ deposited by ALD was measured to have water vapor transmittance rate(WVTR) well below the detection limit($5.0{\times}10^{-5}g/m^2day$) of MOCON Aquatran 2 equipment.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
• /
• pp.425-425
• /
• 2008

The transparent conducting oxides(TCOs) are widely used as electrodes for most flat panel display devices(FPDs), electrodes in solar cells and organic light emitting diodes(OLED). Among them, indium oxide materials are mostly used due to its high electrical conductivity and a high transmittance in the visible spectrum. The present study reports on a study of the electrical and optical properties of IGZO thin films prepared on glass and PET substrates by the combinational magnetron sputtering. We use the targets of IZO and Ga2O3 for the deposition process. In some case the deposition process is coupled with the End-Hall ion-beam treatment onto the substrates before the sputtering. In addition we control the deposition rate to optimize the film quality and to minimize the surface roughness. Then we investigate the effects of the Ar gas pressure and RF power during the sputtering process upon the electrical, optical and morphological properties of thin films. The properties of prepared IGZO thin films have been analyzed by using the XRD, AFM, a-step, 4-point probe, and UV spectrophotometer.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
• /
• pp.926-929
• /
• 2007

A significant progress has been made in the characterization of zinc oxide (ZnO) semiconductor as a new semiconductor layer instead of amorphous Si semiconductor used in thin film transistor due to its high electron mobility at low deposition temperature which is quite suitable for flexible display and OLED devices. The wet pattering of ZnO is another important issue with regard to mass production of ZnO thin film transistor device. However, the wet behavior of ZnO thin film in aqueous wet etching solutions conventionally used un TFT industry has not been reported yet, in this work, wet corrosion behavior of RF magnetron sputtered ZnO thin film in various wet solutions such as phosphoric and nitric acid solutions was studied using by electrochemical analysis. The effects of deposition parameters such as RF power and oxygen partial pressure on corrosion rate are also examined.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
• /
• pp.62-65
• /
• 2007

Conventional semiconductor processes have been utilized to fabricate 3.5-inch OTFT-driven OLEDs with a resolution of $176\;{\times}\;144$ pixels on plastic substrates. By using a PC-OVD method to deposit a pentacene layer and optimizing patterning and the following processes, we could complete a uniform and reliable integration procedure for an active matrix organic light emitting devices on a plastic substrate. The technical importance of ours is the applicability of conventional semiconductor process to organic materials on plastic substrates. Although there are many hurdles to overcome, our approach and technical improvements are proved to be applicable to plastic electronics.

• Bulletin of the Korean Chemical Society
• /
• 제34권8호
• /
• pp.2267-2270
• /
• 2013

A series of blue fluorescent emitters based on triphenylene derivatives were synthesized via the Diels-Alder reaction in moderate yields. The electronic absorption and emission characteristics of the new functional materials were affected by the nature of the substituent on the triphenylene nucleus. Multilayered OLEDs were fabricated with a device structure of: ITO/NPB (50 nm)/EML (30 nm)/Bphen (30 nm)/Liq (2.0 nm)/Al (100 nm). All devices showed efficient blue emissions. Among those, a device using 1 gives the best performances with a high brightness (978 cd $m^{-2}$ at 8.0 V) and high efficiencies (a luminous efficiency of 0.80 cd/A, a power efficiency of 0.34 lm/W and an external quantum efficiency of 0.73% at 20 $mA/cm^2$). The peak wavelength of the electroluminescence was 455 nm with CIEx,y coordinates of (0.17, 0.14) at 8.0 V.

• Journal of Information Display
• /
• 제7권3호
• /
• pp.19-22
• /
• 2006

White polymeric light-emitting devices (WPLEDs) have been fabricated from polyfluorene-based (PFO) blue and MEH-PPV polymer blending systems. A device structure of ITO / PEDOT:PSS / Blending polymer / Blue polymer / LiF / Al was employed. This structure of double emission layers showed significant improvement of white color shift phenomenon. A current efficiency of 4.67 cd/A (3,900 $cd/m^{2}$, 6.4 V) and a brightness value of 17,600 $cd/m^{2}$ at 9.4 V with (0.34, 0.35) CIE coordinates at 5 V and (0.29, 0.29) at 9 V were achieved achieved.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
• /
• pp.514-516
• /
• 2003

We have fabricated an air stable blue emitting organic electroluminescent devices (OLEDs) with a carbazole based emitting molecule, Bis(3-N-ethylcarbazolyl)terephthalidene (BECP). Our device emits strong blue at 472 nm with the luminance efficiency of near 1 lm/W at a voltage and current density of 8 V and 5.7 mA/cm2, respectively, reaching the brightness up to 5000 cd/m2 at 270 mA/cm2. Finally, in order to tune the emission color from blue to green, we have used Bis(3-N-ethylcarbazolyl)cynoterephthalidene (BECCP), a derivative of BECP by adding cyno group in side chain, and compared the electroluminscence (EL) of OLEDS prepared by BECCP to that of BECP based OLEDs.

• 한국전기전자재료학회논문지
• /
• 제19권6호
• /
• pp.563-567
• /
• 2006

Indium tin oxide (ITO) used as an electrode in organic light emitting diodes (OLEDs) and organic thin film transistors (OTFTs) was modified by a self-assembled monolayer (SAM). For device fabrication, surface of the ITO was modified by immersion in a solution including various phosphonic acid at room temperature in order to increase work function of an electrode. The work function of ITO with SAM was measured by Kelvin probe. Work function increase of 0.88 eV was observed in ITO with various SAM. Therefore, ohmic contact is achieved in an interface between ITO and organic semiconductors (pentacene). We analyzed the origin of work function increase of ITO with SAM by X-ray photoelectron spectroscopy. We confirmed that increase of oxygen bonding energy attributed to increase the work function of ITO. These results suggested that ITO with the SAM gives a high possibility for high performance of OLEDS and OTFTs.

• 한국전기전자재료학회논문지
• /
• 제15권5호
• /
• pp.429-434
• /
• 2002

In this paper, multiheterostructure white organic light-emitting device was fabricated by vacuum evaporation. The structure of white organic light-emitting device is ITO/CuPc/TPD/DPBi:DPA/$Alq_3/Alq_3$:DCJTB/BCT/$Alq_3$/Ca/Al. Three primary colors are implemented with DPVBi, Alq$_3$and DCJTB. The maximum EL wavelength of the fabricated white organic light-emitting device is 647nm. And the CIE coordinate is (0.33, 0.33) at 13 V. In the fabrication of white organic light-emitting devices with DCJTB, $Alq_3$, DPVBi, the EL spectrum has two peaks at 492nm, 647nm. Two peaks appeared because the blue light is combined with green light. The maximum wavelength of red light is not changed with applied voltage. After voltage applied, for the first time, the electrons met the holes in the red emission layer and emitted red light. And then the electrons moved to the green emission layer, and blue emission layer continuously. Finally, when all of the emission layer activated, the white light is emitted.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
• /
• pp.428-429
• /
• 2006

In this thesis, verifies electrical-optical characteristics of phosphorescent materials. basic structure of fabricating devices is glass/ITO/$\alpha$-NPD($300{\AA}$)/CBP:Guest($300{\AA}$)/BCP($80{\AA}$)/$Alq_3(100{\AA})$/Al($1000{\AA}$). In efficiency, fabrication of organic light emitting diodes using $Ir(btp)_2acac$ phosphorescent material is external quantum efficiency 0.268% as doping concentration 3%. At CIE coordinates, phosphorescent material $Ir(btp)_2acac$ following materials moves high purity red color(x=0.6686, y=0.3243). The brightness shows $285cd/cm^2$.