• Journal of Information Display
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• v.3 no.1
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• pp.1-5
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• 2002

A series of fully conjugated polymers containing new arylenevinylene units were synthesized and their light-emitting properties were investigated. A bisphosphonate containing tetraphenyl group was made to react with three different dialdehyde monomers to produce fully conjugated alternating copolymers. The photoluminescence (PL) and the electroluminescence (EL) peak wavelengths of the polymers were varied from 500 nm to 460 nm depending on the polymer structure. Single layer EL devices using the polymers as an emissive layer have been fabricated. The single layer EL devices became visible between 12-22 V and emitted blue light.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1334-1337
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• 2005

Orange-yellow phosphor has been synthesized by solid-state method for inorganic EL devices. Zinc sulfide is used as host material for the phosphor and the phosphor consists of copper and manganese as activators. The dependence of the photoluminescence (PL) and electroluminescence(EL) properties on the copper and manganese concentrations has been investigated.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1404-1407
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• 2005

We have fabricated organic light-emitting diodes using poly(N-vinylcarbazole)(PVK) doped with N,N'- diphenyl-N,N'-bis(3-methylphenyl)-[l,l'-biphenyl]- 4,4/-diamine (TPD) as the hole transport layer. TPD molecules act as the trapping sites in PVK and reduce the hole mobility, which can enhance the electronhole balance in the emitting layer, resulting in the enhanced device performance. We have found the optimum ratio of TPD to PVK for the EL efficiency.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.195-198
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• 1998

${\pi}-conjugated$ poly(arylene)s exhibit interesting electrochemical, optical, and electric properties, and various studies have been made on the chemical and physical properties of the poly(arylene)s. Poly(p-phenylene)(PPP) is a well-known highly conductive and highly stable organic material and is the subject of great interest in electronic device applications. (omitted)

• Journal of Information Display
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• v.4 no.2
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• pp.7-12
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• 2003

We discuss main techniques to improve legibility of electroluminescent displays. Emphasis is placed on use of destructive optical interference to cancel ambient light reflected from the back electrode of the device. Basic optical principles and material composition of the optical interference contrast-enhancing stack (CES) are presented. We also describe the improved human factors of electroluminescent devices assisted with a CES. Achromatic contrast is the most important contributor to display's legibility. In some conditions color contrast may also be important. Contributing to both luminance and color contrast enhancement, the contrast-enhancing stack may play an important role in various display applications.

• Bulletin of the Korean Chemical Society
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• v.22 no.9
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• pp.975-978
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• 2001

A novel poly[9,10-diphenylanthracene-4',4"-ylenevinylene-3,6-(N-2-ethyl hexyl)carbazole] containing alternate diphenylanthracene and carbazole unit was synthesized by the Wittig reaction. The obtained polymer was soluble in common organic solvents and thermally stable up to 380 $^{\circ}C.$ The polymer gives rise to bright blue fluorescence both in solution and in thin solid films. The light emitted from the device (ITO/polymer/Al) was greenish-blue in color and clearly visible in daylight.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.10
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• pp.31-36
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• 1999

The $CaSiN_2:Eu$ and $CaSiN_2:Tb$ phosphors were synthesized and analyzed to develop new nitride compound phosphors. $Ca_3N_2$, $Si_3N_4$ and $EuF_3$(or $TbF_3$) powders were mixed, cold-pressed, and sintered to synthesize $CaSiN_2:Eu$ and $CaSiN_2:Tb$ phosphors. Photoluminescence(PL) and electroluminescence(EL) characteristics of the synthesized phosphors were measured and found to be similar to general emission spectra of 뗘 and Tb ion, respecticely. Threshold voltage($V_{th)$) and luminance of the $CaSiN_2:Eu$ TFEL device fabricated by sputtering were 90 V and 1.62 $cd/m^2$ at 280 V, respectively. The charge-voltage(Q-V) and transferred charge-phosphor field($Q_t-F_p$) characteristics of the TFEL devices were also measured.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1735-1737
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• 1999

In this study, several lanthanide complexes such as Eu$(TTA)_3$(Phen). Tb$(ACAC)_3$(Cl-Phen) were synthesized and the white-light electroluminescence (EL) characteristics of their thin films were investigated. where the devices having structures of anode/TPD/Tb$(ACAC)_3$(Cl-Phen)/Eu$(TTA)_3$(Phen)/$Alq_3$ or $Bebq_2$/ cathode and the low work function metal alloy such as Li:Al was used as the electron injecting electrode (cathode). Details on the white-light-emitting characteristics of these device structures were explained by the energy band diagrams of various materials used in these structures, where the energy levels of new materials such as ionization potential (IP) and electron affinity (EA) were measured by cyclic voltametric method.

• Macromolecular Research
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• v.11 no.6
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• pp.471-475
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• 2003

A new poly[2-(2',5'-dimethylphenyl)-1,4-phenylenevinylene] (PDMPPV) that features a bulky 2',5'-dimethylphenyl substituent, which can induce steric hindrance between the PPV backbone and the methyl groups, was designed and synthesized. The polymer structure having no TBB defects was confirmed by $^1$H-NMR and $\^$13/CNMR spectroscopy. The polymer showed good thermal stability with high T$\_$g/. The polymer film showed a maximum absorption at 415 nm with an absorption onset at 480 nm. The maximum emission peak showed at ca. 515 nm, with a shoulder at 530 nm. The turn-on voltages of ITO/PEDOT/PDMPPV/Al and ITO/PDMPPV/Al devices were 8 and 10 V, respectively. The electroluminescence spectrum from the device showed a maximum peak at 510 nm with a shoulder at ca. 535 nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.315-318
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• 1998

Organic light-emitting diodes(OLEDs) or electroluminescent devices have attracted much attention because of their possible application as large-area light-emitting displays. Their structure was based on employing a multilayer device structure containing an emitting layer and a carrier transporting layer of suitable organic materials. In this study, several Tb complexes such as Tb(ACAC)$_3$(Phen), Tb(ACAC)$_3$(Phen-Cl) and Tb(TPB)$_3$(Phen) were synthesized and the photoluminescence(PL) and electroluminescence (EL) characteristics of their thin films were investigated by fabricating the devices having a structure of anode/HTL/terbium-oomplex/ETL/cathode, where TPD was used as an hole transporting and Alq$_3$ and TAZ-Si were used as an electron transporting materials. It was found that the photoluminescence(PL) and electroluminescence(EL) characteristics of these terbium complexes were dependent upon the ligands coordinated to terbium metal. Details on the explanation of electrical transport phenomena of the structure with I-V characteristics of the OLEDs using the trapped-charge-limited current(TCLC) model will be discussed.