Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Institute of Electrical and Electronic Material Engineers
Journal Basic Information
Journal DOI :
The Korean Institute of Electrical and Electronic Material Engineers
Editor in Chief :
Volume & Issues
Volume 24, Issue 12 - Dec 2011
Volume 24, Issue 11 - Nov 2011
Volume 24, Issue 10 - Oct 2011
Volume 24, Issue 9 - Sep 2011
Volume 24, Issue 8 - Aug 2011
Volume 24, Issue 7 - Jul 2011
Volume 24, Issue 6 - Jun 2011
Volume 24, Issue 5 - May 2011
Volume 24, Issue 4 - Apr 2011
Volume 24, Issue 3 - Mar 2011
Volume 24, Issue 2 - Feb 2011
Volume 24, Issue 1 - Jan 2011
Selecting the target year
Simulation of Optical Characteristics of 1.3 μm GaAs-Based GaAsSb/InGaAs and GaAsSb/InGaNAs Quantum Well Lasers for Optical Communication
Park, Seoung-Hwan ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 1~6
DOI : 10.4313/JKEM.2011.24.1.1
Optical gain characteristics of
type-II GaAsSb/InGaNAs/GaAs trilayer quantum well structures were studied using multi-band effective mass theory. The results were compared with those of
GaAsSb/InGaNAs/GaAs trilayer quantum well structures. In the case of
GaAsSb/InGaNAs/GaAs trilayer quantum well structure, the energy difference between the first two subbands in the valence band is smaller than that of
GaAsSb/InGaNAs/GaAs trilayer quantum well structure. Also,
GaAsSb/InGaNAs/GaAs trilayer quantum well structure shows larger optical gain than
GaAsSb/InGaNAs/GaAs trilayer quantum well structure. This means that GaAsSb/InGaNAs/GaAs system is promising as long-wavelength optoelectronic devices for optical communication.
GaN Base Blue LED on Patterned Sapphire Substrate by Wet Etching
Kim, Do-Hyung ; Yi, Yong-Gon ; Yu, Soon-Jae ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 7~11
DOI : 10.4313/JKEM.2011.24.1.7
Sapphire substrate was patterned by a selective chemical wet etching technique, and GaN/InGaN structures were grown on this substrate by MOVPE (Metal Organic Vapor Phase Epitaxy). The surface of grown GaN on patterned sapphire substrate (PSS) has good morphology and uniformity. The patterned sapphire substrate LED showed better light output than conventional LED that improvement 50%. We think these results come from enhancement of internal quantum efficiency by decrease of threading dislocation and increase of light extraction efficiency. Also these LED showed more uniform emission distribution in angle than conventional LED.
Interface Treatment Effect of High Performance Flexible Organic Thin Film Transistor (OTFT) Using PVP Gate Dielectric in Low Temperature
Yun, Ho-Jin ; Baek, Kyu-Ha ; Shin, Hong-Sik ; Lee, Ga-Won ; Lee, Hi-Deok ; Do, Lee-Mi ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 12~16
DOI : 10.4313/JKEM.2011.24.1.12
In this study, we fabricated the flexible pentacene TFTs with the polymer gate dielectric and contact printing method by using the silver nano particle ink as a source/drain material on plastic substrate. In this experiment, to lower the cross-linking temperature of the PVP gate dielectric, UV-Ozone treatment has been used and the process temperature is lowered to
and the surface is optimized by various treatment to improve device characteristics. We tried various surface treatments;
Plasma, hexamethyl-disilazane (HMDS) and octadecyltrichlorosilane (OTS) treatment methods of gate dielectric/semiconductor interface, which reduces trap states such as -OH group and grain boundary in order to improve the OTFTs properties. The optimized OTFT shows the device performance with field effect mobility, on/off current ratio, and the sub-threshold slope were extracted as
, and of 0.75 V/decade, respectively.
Particle Removal on Buffing Process After Copper CMP
Shin, Woon-Ki ; Park, Sun-Joon ; Lee, Hyun-Seop ; Jeong, Moon-Ki ; Lee, Young-Kyun ; Lee, Ho-Jun ; Kim, Young-Min ; Cho, Han-Chul ; Joo, Suk-Bae ; Jeong, Hae-Do ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 17~21
DOI : 10.4313/JKEM.2011.24.1.17
Copper (Cu) had been attractive material due to its superior properties comparing to other metals such as aluminum or tungsten and considered as the best metal which can replace them as an interconnect metal in integrated circuits. CMP (Chemical Mechanical Polishing) technology enabled the production of excellent local and global planarization of microelectronic materials, which allow high resolution of photolithography process. Cu CMP is a complex removal process performed by chemical reaction and mechanical abrasion, which can make defects of its own such as a scratch, particle and dishing. The abrasive particles remain on the Cu surface, and become contaminations to make device yield and performance deteriorate. To remove the particle, buffing cleaning method used in post-CMP cleaning and buffing is the one of the most effective physical cleaning process. AE(Acoustic Emission) sensor was used to detect dynamic friction during the buffing process. When polishing is started, the sensor starts to be loaded and produces an electrical charge that is directly proportional to the applied force. Cleaning efficiency of Cu surface were measured by FE-SEM and AFM during the buffing process. The experimental result showed that particles removed with buffing process, it is possible to detect the particle removal efficiency through obtained signal by the AE sensor.
A Study on Generating Characteristics of Circular Unimorph-Type Piezoelectric Transducer
Park, Choong-Hyo ; Kim, Jong-Wook ; Jeong, Seong-Su ; Chong, Hyon-Ho ; Kim, Myong-Ho ; Park, Tae-Gone ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 22~26
DOI : 10.4313/JKEM.2011.24.1.22
On this paper, a circular unimorph-type piezoelectric transducer was proposed and studied. The transducer was fabricated by attaching a circular-shaped PZT ceramic to a circular plate of brass and output characteristics of the fabricated transducer were then analyzed and measured by changing driving points where the mechanical vibrations were applied. Two conditions depending on the location of vibration were respectively defined as a center forced model and an edge forced model. The resonance frequency and output voltage of the models were simulated by using ANSYS, a FEM(finite element method) program. Based on the results of the analyses, the vibration experiment was conducted and the output characteristics then measured through measurement equipment. As a result, the maximum output characteristics of two models were respectively generated at each resonance frequency and the resonance frequency of the center forced model was lower than the edge forced model.
Luminescent Characteristics of ZnS:Mn,Sm Phosphors Prepared with Various Sm Concentration for White Light Emitting Diodes
Lee, Ji-Young ; Lee, Sang-Jae ; Kim, Tae-Woo ; Yu, Il ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 27~31
DOI : 10.4313/JKEM.2011.24.1.27
ZnS:Mn yellow phosphors doped with Sm for white light emitting diodes were synthesized by solid state reaction method. These sample showed the characteristic X-ray diffraction patterns for main peak (110) of ZnS:Mn,Sm. Photoluminescence excitation spectra originated from
were ranged from 450 nm to 500 nm. The yellow emission at around 580 nm was associated with
ions in ZnS:Mn,Sm phosphors. The highest photolum inescence intensity of the phosphors under 405 nm and 450 nm excitation was obtained at Sm concentration of 1 mol%. The enhanced photoluminescent intensity in the ZnS:Mn,Sm phosphors was interpreted by energy transfer from Sm to Mn. The highest luminescent intensity of white LED was obtained at the epoxy-to-yellow phosphor ratio of 1:3. At this ratio, the CIE chromaticity of the white LED was X=0.3886 and Y=0.2928.
Thickness and Angle Dependent Microcavity Properties in Top-Emission Organic Light-Emitting Diodes
Lee, Won-Jae ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 32~35
DOI : 10.4313/JKEM.2011.24.1.32
Top-emission device has a merit of high aperture ratio and narrow emission spectrum compared to that of bottom-emission one. Emission spectra of top-emission organic light-emitting diodes depending on a layer thickness and view angle were analyzed using a theory of microcavity. Device structure was manufactured to be Al (100 nm)/TPD/
/LiF (0.5 nm)/Al (2 nm)/Ag (30 nm). N,N'-diphenyl-N,N'- di (m-tolyl)-benzidine (TPD) and tris (8-hydroxyquinoline) aluminium (Alq3) were used as a hole-transport layer and emission layer, respectively. And a thickness of TPD and Alq3 layer was varied in a range of 40 nm~70 nm and 60 nm~110 nm, respectively. Angle-dependent emission spectrum out of the device was measured with a device fixed on a rotating plate. Since the top-emission device has a property of microcavity, it was observed that the emission spectrum shift to a longer wavelength region as the organic layer thickness increases, and to a shorter wavelength region as the view angle increases. Layer thickness and view-angle dependent emission spectra of the device were analyzed in terms of microcavity theory. A reflectivity of semitransparent cathode and optical path length were deduced.
Characteristic Evaluation of Medical X-Ray Using High-Voltage Generator with Inverter System
Kim, Young-Pyo ; Cheon, Min-Woo ; Park, Yong-Pil ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 36~41
DOI : 10.4313/JKEM.2011.24.1.36
Medical X-ray has been brought many changes according to the rapid development of high technology. Especially, for high-voltage generator which is the most important in X-ray generation the traditional way is to use high-voltage electric transformers primarily. However, since it is large and heavy and the ripple rate of DC high-voltage applied to X-ray tube is too big, it has a disadvantage of low X-ray production efficiency. To solve these problems, the studies about high-voltage power supply are now proceeding. At present, the high-voltage generator that generates high-voltage by making high frequency using inverter control circuit consisting of semiconductor device is mainly used. High-voltage generator using inverter has advantages in the diagnosis using X-ray including high performance with short-term use, miniaturization of power supply and ripple reduction. In this study, the X-ray high-voltage device with inverter type using pulse width modulation scheme to the control of tube voltage and tube current was designed and produced. For performance evaluation of produced device, the control signal analysis, irradiation dose change and beam quality depending on the load variation of tube voltage and tube current were evaluated.
Wound Recovery of Light Irradiation by White LED
Cheon, Min-Woo ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 42~46
DOI : 10.4313/JKEM.2011.24.1.42
Light can be divided into ultraviolet rays, visible rays, and infrared rays depending on the wavelengths. Visible rays with specific wavelength are those predominantly used for would treatment. Especially low level laser irradiates into cells, effectively stimulating cellular tissues and activating cellular function. This study was intended to verify the effect of white LED irradiation therapy on wound recovery in animal tests by applying white LED irradiator, which was independently designed and developed to emit beams of similar wavelength to that of a laser. The designed LED Irradiator was used to find out how white LED light source affected the skin wound of SD-Rat(Sprague-Dawley Rat). We divided the participants into two groups; white LED irradiation group which was irradiated 1 hour a day for 9 consecutive days, and none irradiation group. The results showed that the study group had lower incidence of inflammation and faster recovery, compared with the control group.
Analysis on Current Limiting Characteristics of a Superconducting Fault Current Limiter (SFCL) with a Peak Currnt Limiting Function
Han, Tae-Hee ; Lim, Sung-Hun ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 47~51
DOI : 10.4313/JKEM.2011.24.1.47
The superconducting fault current limiter (SFCL) with a peak current limiting function according to the initial fault current with the different amplitudes was suggested. The proposed SFCL, which consists of two limiting components, causes only the first superconducting element among two limiting components to be quenched in case that the initial fault current with the lower peak amplitude happens. On the other hand, the initial fault current with the higher peak amplitude makes both the superconducting elements of two limiting components to be quenched, which contributes to the peak current limiting function of the SFCL. To confirm the fault current limiting operation of the proposed SFCL, the short-circuit tests of the SFCL according to the fault angle were carried out and its effective fault current limiting operations could be discussed.
Analysis on Current Limiting Characteristics of the SFCL with Magnetically Coupled Two Coils and YBCO Coated Conductor Due to the Winding Direction and the Turn Number' Ratio Between Two Coils
Lee, Dong-Hyeok ; Du, Ho-Ik ; Kim, Yong-Jin ; Han, Byoung-Sung ; Han, Sang-Chul ; Lee, Jeong-Phil ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 52~56
DOI : 10.4313/JKEM.2011.24.1.52
The ongoing Superconducting Fault Current Limiter(SFCL) development mainly has focused on the application of commercializaton and power system through combining with normal-conducting device, moving away from current-limiting method, which is solely dependant on the existing superconductor. Compared to the structural development above, on the other hand, the research on applying superconducting current-limiting element to SFCL, the heart of SFCL, still has a lot left to do, apart form traditional resistive type SFCL. In this study, we looked into the current limiting characteristic of SFCL using core and coil. YBCO coated conductor with stainless steel stabilizer layer was verified by the excellent of current-limiting element of the resistive type SFCL that has a high Jc and index as well as being superior in mechanical property. Also, we study temperature characteristics and resistance characteristics, max voltage, response time and current-limiting ability that can be an indicator as current-limiting element while applying to superconducting current-limiting element caused by variation of winding direction, winding ratio of SFCL using core and coil.
The Design of a Power Supply for Planer Type of the Dielectric Barrier Discharge Ozone Reactor with Impedance Matching
Kim, Bong-Seong ; Shin, Young-Chul ; Ko, Kwang-Cheol ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 57~63
DOI : 10.4313/JKEM.2011.24.1.57
Dielectric Barrier Discharge (DBD) reactor with sinsodual AC type of power supply is very widely adopted for its compact size and effective discharging mechanism to generate high density of ozone radicals. However, at the aspect of design on power supply, its optimal switching conditions and topology is achieved by empirical test. Therefore, throughout this paper, it is proposed a design method of DBD power supply to guarantee a maximum ozone yield rate in accordance with DBD reactor modification and impedance variation when rapid gas discharging in the DBD reactor is proceeded.
Characteristic Investigation on Super-Hydrophobicity of PTFE Thin Films Deposited on Al Substrates Using RF-Magnetron Sputtering Method
Bae, Kang ; Kim, Hwa-Min ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 64~69
DOI : 10.4313/JKEM.2011.24.1.64
Super-hydrophobic properties have been achieved on the rf-sputtered polytetrafluoroethylene(PTFE) films deposited on etched aluminum surfaces. The microstructural evolution created after etching has been investigated by FESEM. The water contact angle over
can be achieved on the rf-sputtered ultra-tihn PTFE film less than 10 nm coated on aluminum surface etched with 7 wt.%, 12.5 wt.%, and 15 wt.% HCl concentration for 12 min. XPS analysis have revealed the presence of a large quantity of
groups in the rf-sputtered PTFE films that effectively can reduce the surface energy of etched aluminum. The presence of patterned morphology along with the low surface energy at the rf-sputtered PTFE coating makes the aluminum surface with high super-hydrophobic property.
Nanoscale Double Interfacial Layers for Improved Photovoltaic Effect of Polymer Solar Cells
Lee, Young-In ; Park, Byoung-Choo ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 70~75
DOI : 10.4313/JKEM.2011.24.1.70
We introduced nanoscale interfacial layers between the PV layer and the cathode in poly (3-hexylthiophene):methanofullerene bulk-heterojunction polymer photovoltaic (PV) cells. The nanoscale double interfacial layers were made of ultrathin poly (oxyethylenetridecylether) surfactant and low-work-function alloy-metal of Al:Li layers. It was found that the nanoscale interfacial layers increase the photovoltaic performance, i.e., increasing short-circuit current density and fill factor with improved device stability. For PV cells with the nanoscale double interfacial layers, an increase in power conversion efficiency of
was achieved, compared to that of the control devices (
) without the double interfacial layers.
ITO/CNT Nano Composites as a Counter Electrode for the Dye-Sensitized Solar Cell Applications
Park, Jong-Hyun ; Pammi, S.V.N ; Jung, Hyun-June ; Cho, Tae-Yeon ; Yoon, Soon-Gil ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 76~80
DOI : 10.4313/JKEM.2011.24.1.76
The ITO/Cabon Nano Tube (CNT) nano composites were deposited by nano cluster deposition (ITO) and arc discharge deposition (CNT) on glass substrates. The structural, optical and photovoltaic performance of ITO/CNT nano composites as a counter electrode of dye-sensitized solar-cells (DSSCs) such films were investigated. At low temperature below
, the ITO films deposited on CNT. The ITO/CNT nano composit showed a good optical and electrical property for the counter electrode of DSSCs. When the as-prepared ITO/CNT nano composites are used for the counter electrodes, the photovoltaic parameters are
= 0.69 V,
= 5.69 mA/
, FF = 0.32, and
= 0.53 %. The ITO/CNT nano composites showed the possibility for the counter electrode applications of DSSCs.
System Implementation and Algorithm Development for Classification of the Activity States Using 3 Axial Accelerometer
Noh, Yun-Hong ; Ye, Soo-Young ; Jeong, Do-Un ;
Journal of the Korean Institute of Electrical and Electronic Material Engineers, volume 24, issue 1, 2011, Pages 81~88
DOI : 10.4313/JKEM.2011.24.1.81
A real time monitoring system from a PC has been developed which can be accessed through transmitted data, which incorporates an established low powered transport system equipped with a single chip combined with wireless sensor network technology from a three-axis acceleration sensor. In order to distinguish between static posture and dynamic posture, the extracted parameter from the rapidly transmitted data needs differentiation of movement and activity structures and status for an accurate measurement. When results interpret a static formation, statistics referring to each respective formation, known as the K-mean algorithm is utilized to carry out a determination of detailed positioning, and when results alter towards dynamic activity, fuzzy algorithm (fuzzy categorizer), which is the relationship between speed and ISVM, is used to categorize activity levels into 4 stages. Also, the ISVM is calculated with the instrumented acceleration speed on the running machine according to various speeds and its relationship with kinetic energy goes through correlation analysis. With the evaluation of the proposed system, the accuracy level stands at 100% at a static formation and also a 96.79% accuracy with kinetic energy and we can easily determine the energy consumption through the relationship between ISVM and kinetic energy.