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Papers by Taehyoung Zyung

Research paper thumbnail of Gypsum material modified with emulsion polymerizate

Research paper thumbnail of Ultrafast Imaging of Optical Damage in PMMA

Laser Induced Damage in Optical Materials: 1987

Research paper thumbnail of Organic transistors using polymeric gate dielectrics

In this study, to fabricate organic thin film transistors (OTFT), polyvinyl alcohol (PVA) formed ... more In this study, to fabricate organic thin film transistors (OTFT), polyvinyl alcohol (PVA) formed gate dielectrics by using a spin coating process. From the electrical measurements, the current-voltage (I-V) characteristics of the device with PVA gate dielectrics were similar to these obtained by usi...

Research paper thumbnail of Thermoelectric properties of silicide/silicon hetero-junction structure

Research paper thumbnail of Wireless Power Transmission to OLED Lighting Panel with Magnetically Coupled Resonator

Research paper thumbnail of Novel Method for Combining Flexible Organic Light-Emitting Diodes with Organic Thin-Film Transistors

Journal of the Korean Physical Society, 2005

We present a new method of driving an organic light-emitting diode (OLED) with an organic thin-fi... more We present a new method of driving an organic light-emitting diode (OLED) with an organic thin-film transistor (OTFT). The OTFT and the OLED were fabricated on separate plastic substrates and both devices were laminated with silver paste. After driving a 2 ◊ 2 mm 2 OLED with an OTFT device, we obtained 180 cd/m 2 at a current density of 5 mA/cm 2 from the green OLED by using an OTFT with mobility, on-o ratio, threshold voltage, and subthreshold slope of 0.21 cm 2 /V·s, 10 3 , 32 V, and 20 V/decade, respectively.

Research paper thumbnail of Fabrication of Two-dimensional ZnO-NiO Hollow Half Sphere Arrays

ECS Meeting Abstracts, 2009

not Available.

Research paper thumbnail of Low-voltage and high-gain pentacene inverters with plasma-enhanced atomic-layer-deposited gate dielectrics

Applied Physics Letters, 2006

In order for an organic inverter to be used as a basic building block for a circuit operation, a ... more In order for an organic inverter to be used as a basic building block for a circuit operation, a wide swing range, a high gain, a low operation voltage, and an absence of hysteresis are highly required. An organic inverter with a full swing and a high gain can be obtained through ...

Research paper thumbnail of Versatile porous graphene flakes derived from alkali metal carbonates using an ultrafast and sulfuric acid-free solid-state oxidation reaction

Nanoscale, Jan 21, 2018

Herein, we report on an unprecedented synthetic method for single-layered GO that takes just a fe... more Herein, we report on an unprecedented synthetic method for single-layered GO that takes just a few tens of minutes. This rationally designed solid-state oxidation based on alkali metal carbonates (Li2CO3, Na2CO3, K2CO3) involves a molten salt reaction, which enables the effective exfoliation and oxidation of graphene layers without using H2SO4 and KMnO4. The advantage of this approach is not only the ability to avoid the introduction of strong acid reactants in the reaction process, but this approach also leads to a 4.2 times larger specific surface area than conventional GO. For these reasons, we anticipate that this green, safe, fast and effective approach enables practical applications in graphene-based energy storage and light-absorbing black materials.

Research paper thumbnail of Electroluminescence of Photodegraded Poly(p-Phenylene-Vinylene) Derivatives by Ultraviolet Laser Light

Mol Cryst Liquid Cryst, 1997

ABSTRACT We report the observations of electroluminescence of photodegraded poly(p-phenylenevinyl... more ABSTRACT We report the observations of electroluminescence of photodegraded poly(p-phenylenevinylene) derivatives film which was irradiated with laser light at a wavelength in the region of ultraviolet. EL spectral change for different polymers shows different behaviour. Electroluminescence and photoluminescence intensities of PPV decreases rapidly and the intensities in the blue region become relatively severe without peak shift. MEH-PPV shows the blue shift of the peak in EL spectra with negligible intensity decrement. Spectroscopic results of the PPV film degraded by UV light support the photodegradation occurred by chain-scission process.

Research paper thumbnail of Silicon Nanowire Based Thermoelectric Device

Research paper thumbnail of Dielectric Surface Treatment Effects on Organic Thin-film Transistors

Korean Journal of Materials Research

Research paper thumbnail of Light-emitting devices with polymer-organic heterostructure

Journal of the Optical Society of Korea

Research paper thumbnail of Improved Contact Properties for Organic Thin-Film Transistors Using Self-Assembled Monolayer

Japanese Journal of Applied Physics, 2004

ABSTRACT

Research paper thumbnail of Method of manufacturing organic/polymer electroluminescent device

Research paper thumbnail of SnO2–ZnO hybrid nanofibers-based highly sensitive nitrogen dioxides sensor

Sensors and Actuators B Chemical, Mar 4, 2010

SnO 2-ZnO hybrid nanofibers were fabricated by combining the electrospinning and the pulsed laser... more SnO 2-ZnO hybrid nanofibers were fabricated by combining the electrospinning and the pulsed laser deposition methods. After calcining at 600 • C, the nanocrystalline SnO 2 coated ZnO nanofibers with a random network structure were obtained. The fiber diameter and the size of SnO 2 deposit were 55-80 nm and 10-15 nm, respectively. SnO 2-ZnO hybrid nanofibers-based sensor exhibited very high gas response to NO 2 concentration as low as 400 ppb level at 200 • C.

Research paper thumbnail of Thermoelectric Device and Fabricating Method Thereof

Research paper thumbnail of Structure of polymeric/organic electroluminescent device using ionomer as charge transport layer and method of making the same

Research paper thumbnail of Longevity of Organic Light-Emitting Devices by Means of Polyacrylate Passivation Layers Formed by Using Spin Coating Method

Http Dx Doi Org 10 1080 15421400390264171, Jul 15, 2010

ABSTRACT We fabricate organic light-emitting devices with polyacrylate passivation layers formed ... more ABSTRACT We fabricate organic light-emitting devices with polyacrylate passivation layers formed by using spin coating method and compare the rate of degradation to an organic light-emitting device without the passivation layer. The fabrication process of passivation layer did not influence the electrical and the emissive properties of the device. Polyacrylate passivation layers enhanced the longevity of the device than that of the non-encapsulated device, and its behavior was dependent on the polyacrylate film thickness.

Research paper thumbnail of Analysis of the charge transport in pi-conjugated materials using generalized Langevin equation

Appl Phys Lett, 2006

The complex dielectric constants of several pi-conjugated materials are measured, and generalized... more The complex dielectric constants of several pi-conjugated materials are measured, and generalized Langevin equation is used to analyze the dielectric behavior in the frequency domain. From the results of a fitting of the experimental data, all of the dielectric behaviors are well interpreted by the generalized Langevin equation which strongly suggests that the mechanism of the charge carrier transport in pi-conjugated organic and polymeric materials is diffusion at dc and low frequencies and an oscillatory motion at (or near) phonon frequencies, and in between, a mixed mode of these two mechanisms.

Research paper thumbnail of Gypsum material modified with emulsion polymerizate

Research paper thumbnail of Ultrafast Imaging of Optical Damage in PMMA

Laser Induced Damage in Optical Materials: 1987

Research paper thumbnail of Organic transistors using polymeric gate dielectrics

In this study, to fabricate organic thin film transistors (OTFT), polyvinyl alcohol (PVA) formed ... more In this study, to fabricate organic thin film transistors (OTFT), polyvinyl alcohol (PVA) formed gate dielectrics by using a spin coating process. From the electrical measurements, the current-voltage (I-V) characteristics of the device with PVA gate dielectrics were similar to these obtained by usi...

Research paper thumbnail of Thermoelectric properties of silicide/silicon hetero-junction structure

Research paper thumbnail of Wireless Power Transmission to OLED Lighting Panel with Magnetically Coupled Resonator

Research paper thumbnail of Novel Method for Combining Flexible Organic Light-Emitting Diodes with Organic Thin-Film Transistors

Journal of the Korean Physical Society, 2005

We present a new method of driving an organic light-emitting diode (OLED) with an organic thin-fi... more We present a new method of driving an organic light-emitting diode (OLED) with an organic thin-film transistor (OTFT). The OTFT and the OLED were fabricated on separate plastic substrates and both devices were laminated with silver paste. After driving a 2 ◊ 2 mm 2 OLED with an OTFT device, we obtained 180 cd/m 2 at a current density of 5 mA/cm 2 from the green OLED by using an OTFT with mobility, on-o ratio, threshold voltage, and subthreshold slope of 0.21 cm 2 /V·s, 10 3 , 32 V, and 20 V/decade, respectively.

Research paper thumbnail of Fabrication of Two-dimensional ZnO-NiO Hollow Half Sphere Arrays

ECS Meeting Abstracts, 2009

not Available.

Research paper thumbnail of Low-voltage and high-gain pentacene inverters with plasma-enhanced atomic-layer-deposited gate dielectrics

Applied Physics Letters, 2006

In order for an organic inverter to be used as a basic building block for a circuit operation, a ... more In order for an organic inverter to be used as a basic building block for a circuit operation, a wide swing range, a high gain, a low operation voltage, and an absence of hysteresis are highly required. An organic inverter with a full swing and a high gain can be obtained through ...

Research paper thumbnail of Versatile porous graphene flakes derived from alkali metal carbonates using an ultrafast and sulfuric acid-free solid-state oxidation reaction

Nanoscale, Jan 21, 2018

Herein, we report on an unprecedented synthetic method for single-layered GO that takes just a fe... more Herein, we report on an unprecedented synthetic method for single-layered GO that takes just a few tens of minutes. This rationally designed solid-state oxidation based on alkali metal carbonates (Li2CO3, Na2CO3, K2CO3) involves a molten salt reaction, which enables the effective exfoliation and oxidation of graphene layers without using H2SO4 and KMnO4. The advantage of this approach is not only the ability to avoid the introduction of strong acid reactants in the reaction process, but this approach also leads to a 4.2 times larger specific surface area than conventional GO. For these reasons, we anticipate that this green, safe, fast and effective approach enables practical applications in graphene-based energy storage and light-absorbing black materials.

Research paper thumbnail of Electroluminescence of Photodegraded Poly(p-Phenylene-Vinylene) Derivatives by Ultraviolet Laser Light

Mol Cryst Liquid Cryst, 1997

ABSTRACT We report the observations of electroluminescence of photodegraded poly(p-phenylenevinyl... more ABSTRACT We report the observations of electroluminescence of photodegraded poly(p-phenylenevinylene) derivatives film which was irradiated with laser light at a wavelength in the region of ultraviolet. EL spectral change for different polymers shows different behaviour. Electroluminescence and photoluminescence intensities of PPV decreases rapidly and the intensities in the blue region become relatively severe without peak shift. MEH-PPV shows the blue shift of the peak in EL spectra with negligible intensity decrement. Spectroscopic results of the PPV film degraded by UV light support the photodegradation occurred by chain-scission process.

Research paper thumbnail of Silicon Nanowire Based Thermoelectric Device

Research paper thumbnail of Dielectric Surface Treatment Effects on Organic Thin-film Transistors

Korean Journal of Materials Research

Research paper thumbnail of Light-emitting devices with polymer-organic heterostructure

Journal of the Optical Society of Korea

Research paper thumbnail of Improved Contact Properties for Organic Thin-Film Transistors Using Self-Assembled Monolayer

Japanese Journal of Applied Physics, 2004

ABSTRACT

Research paper thumbnail of Method of manufacturing organic/polymer electroluminescent device

Research paper thumbnail of SnO2–ZnO hybrid nanofibers-based highly sensitive nitrogen dioxides sensor

Sensors and Actuators B Chemical, Mar 4, 2010

SnO 2-ZnO hybrid nanofibers were fabricated by combining the electrospinning and the pulsed laser... more SnO 2-ZnO hybrid nanofibers were fabricated by combining the electrospinning and the pulsed laser deposition methods. After calcining at 600 • C, the nanocrystalline SnO 2 coated ZnO nanofibers with a random network structure were obtained. The fiber diameter and the size of SnO 2 deposit were 55-80 nm and 10-15 nm, respectively. SnO 2-ZnO hybrid nanofibers-based sensor exhibited very high gas response to NO 2 concentration as low as 400 ppb level at 200 • C.

Research paper thumbnail of Thermoelectric Device and Fabricating Method Thereof

Research paper thumbnail of Structure of polymeric/organic electroluminescent device using ionomer as charge transport layer and method of making the same

Research paper thumbnail of Longevity of Organic Light-Emitting Devices by Means of Polyacrylate Passivation Layers Formed by Using Spin Coating Method

Http Dx Doi Org 10 1080 15421400390264171, Jul 15, 2010

ABSTRACT We fabricate organic light-emitting devices with polyacrylate passivation layers formed ... more ABSTRACT We fabricate organic light-emitting devices with polyacrylate passivation layers formed by using spin coating method and compare the rate of degradation to an organic light-emitting device without the passivation layer. The fabrication process of passivation layer did not influence the electrical and the emissive properties of the device. Polyacrylate passivation layers enhanced the longevity of the device than that of the non-encapsulated device, and its behavior was dependent on the polyacrylate film thickness.

Research paper thumbnail of Analysis of the charge transport in pi-conjugated materials using generalized Langevin equation

Appl Phys Lett, 2006

The complex dielectric constants of several pi-conjugated materials are measured, and generalized... more The complex dielectric constants of several pi-conjugated materials are measured, and generalized Langevin equation is used to analyze the dielectric behavior in the frequency domain. From the results of a fitting of the experimental data, all of the dielectric behaviors are well interpreted by the generalized Langevin equation which strongly suggests that the mechanism of the charge carrier transport in pi-conjugated organic and polymeric materials is diffusion at dc and low frequencies and an oscillatory motion at (or near) phonon frequencies, and in between, a mixed mode of these two mechanisms.