La presente invention concerne un procede de fabrication pour un substrat qui possede une microstructure. Le procede de fabrication pour un substrat qui possede une microstructure comprend les etapes suivantes : la formation d'une microstructure sur la surface superieure d'un substrat auxiliaire ; l'application d'une solution de base sur la microstructure ; la formation d'un substrat de base qui couvre la microstructure en thermo-traitant la solution de base ; et l'elimination du substrat auxiliaire a partir du substrat de base.

The luminance mechanisms of the white organic light-emitting devices (WOLEDs) with a charge generation layer (CGL) consisting of a tungsten oxide layer and a 5,6,11,12-tetraphenyltetracene (rubrene) doped N,N',-bis-(1-naphthyl)-N,N'-diphenyl1-1'-biphenyl-4,4'-diamine (NPB) layer were investigated. Current densities and luminances of the WOLEDs increased with increasing a rubrene doping concentration because the formation of excitons in the rubrene-doped NPB layer increased due to the more exciton trapping in rubrene molecules and the delay of the electron injection due to the insertion of the litium qunolate layer. The yellow light emitted from the rubrene-doped NPB layer in the CGL combined with the blue light from the main emitting layer of the WOLEDs, resulting in the emission of the white light. The ratio between the yellow and the blue color peak intensities of the electroluminescence spectra for the WOLEDs was controlled by the rubrene doping concentration. The Commission Internationale de l'Eclairage coordinates of the fabricated WOLED were (0.31, 0.42) at 740.7 cd/m2, indicative of white emission color.

White organic light-emitting devices (WOLEDs) were fabricated by combining a blue emitting organic light-emitting devices (OLEDs) and a color conversion layer made of yttrium aluminum garnet phosphors and CdSe/ZnS quantum dots (QDs) embedded into polymethylmethacrylate. When the ratio of phosphors and QDs changed, a good color balance was achieved at a ratio of 1:5, and the maximum luminance of 18.21 cd/m(2) was obtained. As the applied voltage varied from 12 to 16 V, Commission Internationale de l'Eclairage coordinates shifted only slightly from (0.32, 0.34) to (0.30, 0.33), indicating a good color stability.

The optical properties of white organic light-emitting devices (WOLEDs) fabricated utilizing a CaAl12O19:Mn and Zn2SiO4:Mn phosphor layer were investigated. X-ray diffraction patterns for CaAl12O19:Mn and Zn2SiO4:Mn phosphors showed that Mn ions in the CaAl12O19:Mn phosphors were completely substituted into Ca ions and that Mn ions in the Zn2SiO4:Mn phosphors were completely substituted into Zn ions. Field emission scanning electron microscopy images showed that the size of the CaAl12O19:Mn phosphor was approximately between 0.1 and 3 microm, and that the size of the Zn2SiO4:Mn phosphor was smaller than 7 microm. The color coordinates of the electroluminescence spectra for WOLEDs with phosphor thicknesses of 0.25 and 0.35 mm shifted to the white emission side because the generated blue light from the blue OLEDs combined with the red and green lights was converted by the CaAl12O19:Mn and the Zn2SiO4:Mn phosphor down-conversion layers.

The current density and the luminance efficiency of the organic light-emitting devices (OLEDs) with a cesium nitrate (CsNO3)/lithium quinolate (Liq) electron injection layer (EIL) were larger than those of the OLEDs with a Liq EIL. Residual Cs ions or cesium oxides in the OLEDs decreased the electron affinity of the cathode electrode, resulting in an improvement of the electron injection efficiency and the luminance efficiency. Electron only devices, which are elements being able to flow only electrons, showed that the electron injection magnitude was increased due to the insertion of the CsNO3 EIL into OLEDs.

The electrical and optical properties of blue organic light-emitting devices (OLEDs) containing a mixed host emitting layer (EML) consisting of a 1,3-bis(carbazole-9-yl)benzene (mCP) layer and a 3-tert-butyl-9,10-di(naphtha-2-yl)anthracene (TBADN) layer were investigated. The driving voltage of the OLEDs with a mixed host EML was smaller than that of the OLEDs with a single EML. The electroluminescence spectra for OLEDs containing a mixed host EML showed a dominant peak related to the mCP or the TBADN layer. The color coordinates of the OLEDs containing a 5% TBADN-doped mCP EML were (0.146, 0.091), indicative of the deep blue color coordinates.

The electrical and the optical properties of polymer light-emitting devices (PLEDs) fabricated utilizing a graphene hole injection layer (HIL) were investigated to clarify the hole injection enhancement caused by the insertion of the graphene HIL. The graphene was synthesized by using chemical vapor deposition, and the PLEDs with a graphene HIL were fabricated by using spin-casting method. The average transmittance for the graphene film with a thickness of 10 nm was approximately 90%, and the surface of the poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layer deposited on a graphene layer was smoother than that of the PEDOT: PSS deposited on an indium-tin-oxide layer. While the hole current of the PLEDs with a graphene HIL larger than that of the PLEDs without a graphene layer because of the high conductivity of the graphene film, the luminance efficiency was lower due to the leakage of holes that had not recombined with electrons. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3604779] All rights reserved.

The electrical and optical properties of organic light-emitting devices (OLEDs) with three periods of 4,7-diphenyl-1,10-phenanthroline (BPhen)/aluminum tris(8-hydroxyquinolate) (Alq(3)) multiple heterostructures acting as an electron transport layer (ETL) were investigated. While the leakage current of OLEDs with multiple heterostructures was smaller than that of OLEDs without multiple heterostructures, the luminance efficiency was larger than that of OLEDs without multiple heterostructures. The BPhen layers in the multiple heterostructures blocked holes from the emitting layer (EML) to the ETL, and they enhanced the electron injection from the cathode to the EML, resulting in an increase in the luminance efficiency.

White organic light-emitting devices (WOLEDs) were fabricated utilizing a hybrid poly(2-methoxy-5-(2-ethyhexoxy)-1,4-phenylene vinylene) (MEH-PPV)/2-methyl-9,10-di(2-naphthyl) anthracene (MADN) emitting layer. Nano-sized pores were formed on the surface of the MEH-PPV layer by using a selective etching of polystyrene (PS) in the MEH-PPV:PS blending layer due to the enhancement of the direct hole injection from hole injection layer (HIL) into the MADN layer. The contact area between the HIL and the MADN layer was widened with increasing ratio of the PS in the MEH-PPV:PS blending polymer, resulting in the enhancement of the electroluminescence intensity for MADN. One of the WOLEDs utilizing the polymer with the ratio of 1:2 (0.44, 0.31) met the requirements of the Commission Internationale de l'Eclairage for the white color.

White organic light-emitting devices (OLEDs) were fabricated utilizing a CaAl12O19:Mn phosphor layer. X-ray diffraction patterns for CaAl12O19:Mn phosphors showed that Mn ions in the CaAl12O19:Mn phosphors were completely substituted into Ga ions. Field-emission-scanning electron microscopy images showed that the sizes of the CaAl12O19:Mn phosphor crystals were approximately between 0.1 and 3 mu m. Although a broad band approximately between 250 and 550 nm of an excitation spectrum for CaAl12O19:Mn appeared, peaks were observed at 639, 654, and 665 nm of the fluorescence emission spectrum. The color coordinates of the electroluminescence spectra for white OLEDs with phosphor thicknesses of 0.25 and 0.35 mm shifted to the white emission side because the generated blue light from the blue OLEDs combined with the red light converted by the CaAl12O19:Mn phosphor down-conversion layer. The color conversion efficiency of white OLEDs was significantly affected by the excitation source and the thickness of the phosphor layer. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3409746] All rights reserved.

Zn2SiO4:Mn phosphor layers used in this study were synthesized by using the sol–gel method and printed on the glass substrates by using a vehicle solution and a heating process. Organic/inorganic hybrid organic light-emitting devices (OLEDs) utilizing a Zn2SiO4:Mn color-conversion layer were fabricated. X-ray diffraction data for the synthesized Zn2SiO4:Mn phosphor films showed that the Zn ions in the phosphor were substituted into Mn ions. The electroluminescence (EL) spectrum of the deep blue OLEDs showed that a dominant peak at 461nm appeared. The photoluminescence spectrum for the Zn2SiO4:Mn phosphor layer by using a 470nm excitation source showed that a dominant peak at 527nm appeared, which originated from the 4T1–6A1 transitions of Mn ions. The appearance of the peak around 527nm of the EL spectra for the OLEDs fabricated utilizing a Zn2SiO4:Mn phosphor layer demonstrated that the emitted blue color from the deep blue OLEDs was converted into a green color due to the existence of the color-conversion layer. The luminescence mechanisms of organic/inorganic hybrid OLEDs fabricated utilizing a Zn2SiO4:Mn color-conversion layer are described on the basis of the EL and PL spectra.

Electron injection mechanisms of the luminance efficiency of green organic light-emitting devices (OLEDs) fabricated utilizing a cesium carbonate (Cs2CO3)/fullerene (C60) heterostructure acting as an electron injection layer (EIL) were investigated. Current density–voltage and luminance–voltage measurements showed that the current densities and the luminances of the OLEDs with a Cs2CO3 or Cs2CO3/C60 EIL were higher than that of the OLEDs with a Liq EIL. The luminance efficiency of the OLEDs with a Cs2CO3 EIL was almost three times higher than that of the OLEDs with a Liq EIL. Because the electron injection efficiency of the Cs2CO3 layer in OLEDs was different from that of the C60 layer, the luminance efficiency of the OLEDs with a double EIL consisting of a Cs2CO3 layer and a C60 layer was smaller than that of the OLEDs with a Cs2CO3 EIL. The electron injection mechanisms of OLEDs with a Cs2CO3 and C60 double EIL are described on the basis of the experimental results.

The luminance efficiency of the blue organic light-emitting devices (OLEDs) fabricated utilizing a double emitting layer (DEML) with a 4,4'-Bis(2,2-diphenyl-ethen-1-yl)diphenyl (DPVBi) layer doped with 4,4'-Bis[4-(diphenylamino)styryl]biphenyl (BDAVBi) fluorescence dopant and a 4,4'-Bis(carbazol-9-yl)biphenyl (CBP) layer doped with a bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium III (FIrpic) phosphorescence dopant at 20mA/cm(2) was 6.2 cd/A, indicative of highly efficient OLEDs. Electroluminescence spectra for the OLEDs with a DEML showed that a dominant peak at 469nm corresponding to the BDAVBi doped DPVBi layer together with a shoulder at 491nm related to the combination of the BDAVBi doped DPVBi layer and the FIrpic doped CBP layer appeared.

Electrical and optical properties of blue organic light-emitting devices (OLEDs) with doped or undoped emitting layers (EMLs) consisting of a heterostructure layer or a single layer were investigated. The driving voltage of the OLEDs with an undoped heterostructure multiple EML was lower than those of both OLEDs with a single EML and a doped heterostructure multiple EML. The electroluminescence spectra of the OLEDs with an undoped and a doped heterostructure EMLs showed dominant peaks related to two heterostructure layers.

The luminance efficiency of the blue organic light-emitting devices (OLEDs) with a mixed host emitting layer (EML) consisting of a 2-t-butyl-9,10-di-2-naphthylanthracene (TBADN) and 4,4′-Bis[4-(diphenylamino)styryl]biphenyl (BDAVBi)-doped 1,3-bis(carbazol-9-yl)benzene (mCP) layer at 20 mA/cm2 was 5.78 cd/A, indicative of highly efficient OLEDs. Electroluminescence spectra for the OLEDs with a mixed host EML showed that a dominant peak at 467 nm corresponding to the BDAVBi doped mCP layer together with a shoulder at 491 nm related to the combination of the TBADN doped mCP layer and the BDAVBi doped mCP layer appeared.

While the hole transport decreased in the mixed layer in the organic light-emitting devices (OLEDs) with an Al:lithium quinolate (Liq) mixed layers in the electron transport layer (ETL), the electron injection increased the Al:Liq mixed layer. The enhancement of luminance efficiency in the OLEDs with an Al:Liq mixed layer in the ETL originated from the more balance between the electrons and the holes in the emitting layer due to the decrease in the hole injection and the increase in the electron injection resulting from the existence of the Al:Liq mixed layer.

While the current density of the organic light-emitting devices (OLEDs) with 5,6,11,12-tetraphenylnaphthacene (rubrene) layers in both the hole transport layer (HTL) and the emitting layer (EML) was lower than those of the OLEDs without a rubrene layer or with a rubrene layer in only a HTL or an EML, the luminance efficiency of the OLEDs with rubrene layers in both the HTL and the EML were significantly enhanced. While the rubrene layer in the HTL acting as a hole trap decreased the hole mobility of the HTL, the rubrene layer in the EML acting as an emitting site increased the luminance.

While the current densities of hole only devices with a 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane (F-4-TCNQ) doped N,N'-bis-(1-naphthyl)- N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB) hole transport layer (HTL) slightly changed with increasing F-4-TCNQ doping concentration, those of hole only devices with a F-4-TCNQ doped 4,4',4 ''-tris(N-(2-naphthyl)-Nphenylamino)triphenylamine (2-TNATA) HTL significantly increased. The hole injection and hole transport of hole only devices were enhanced by inserting an ultra thin F-4-TCNQ layer between an indium-tin-oxide layer and a NPB HTL or a 2-TNATA HTL, regardless of the HTL materials. These results indicate that the hole injection and hole transport in OLEDs utilizing a F-4-TCNQ doped HTL or a F-4-TCNQ thin layer is enhanced.