• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1057-1060
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• 2004

In this study, the wear characteristics of five different dental composite resins cured by conventional halogen light and LED light sources were investigated. Five different dental composite resins of Surefil, Z100, Dyract AP, Fuji II LC and Compoglass were worn against a zirconia ceramic ball using a pin-on-disk type wear tester with 15 N contact force in a reciprocal sliding motion with sliding distance of 10 mm/cycle at 1Hz under the room temperature dry condition. The wear variations of dental composite resins were linearly increased as the number of cycles increased. It was observed that the wear resistances of these specimens were in the order of Dyract AP ＆gt; Surefil ＆gt; Compoglass ＆gt; Z100 ＆gt; Fuji II LC. On the morphological observations by SEM, the large crack formation on the sliding track of Fuji II LC specimen was the greatest among all resin composites. Dyract AP showed the least wear with few surface damage. There is no significant difference in wear performance between conventional halogen light curing and light emitting diodes curing sources. It indicates that a light emitting diodes (LED) source can replace a halogen light source as a curing unit for composite resin restorations.

• 조명전기설비학회논문지
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• 제19권1호
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• pp.9-14
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• 2005

Fabry-Perot 레이저 다이오드의 missing mode의 원인으로 의심되는 활성층 내의 구조적 결함과 리플의 영향을 TDLM(time domain laser model)방식을 사용하여 모델링하였다. 보다 정확한 모델링의 결과를 얻기 위하여 여러가지 비선형 효과를 추가 고려하였다. 이를 이용하여 레이저 다이오드를 시뮬레이션하였고, 모드 스펙트럼(mode spectrum)을 구하였다. 실제 레이저 다이오드의 missing mode를 측정하기 위한 실험 장비를 구성하여 측정 결과를 추출하였고, 시뮬레이션과 측정 실험 결과로부터 결론을 내렸다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.486-488
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• 2009

High efficiency deep blue and pure white phosphorescent organic light emitting diodes were developed using a new deep blue phosphorescent dopant, tris((3,5-difluoro-4-cyanophenyl)pyridine) iridium (FCNIr). A high quantum efficiency of 9.1 % with a color coordinate of (0.15, 0.16) at 1,000 cd/$m^2$ was obtained in the deep blue device and a high quantum efficiency of 15.2 % with a color coordinate (0.30, 0.32) was obtained in the pure white organic light-emitting diodes. The quantum efficiency of the pure white device is the best quantum efficiency value reported in the pure white device up to now.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.348-349
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• 2007

This paper describes the electrical characteristics of polycrystalline (poly) 3C-SiC thin film diodes, in which poly 3C-SiC thin films on n-type and p-type Si wafers, respectively, were deposited by APCVD using HMDS, Hz, and Ar gas at $1180^{\circ}C$ for 3 hr. The schottky diode with Au/poly 3C-SiC/Si(n-type) structure was fabricated. Its threshold voltage ($V_d$), breakdown voltage, thickness of depletion layer, and doping concentration ($N_D$) values were measured as 0.84 V, over 140 V, 61nm, and $2.7\;{\times}\;10^{19}\;cm^3$, respectively. The p-n junction diodes fabricated on the poly 3C-SiC/Si(p-type) were obtained like characteristics of single 3C-SiC p-n junction diodes. Therefore, poly 3C-SiC thin film diodes will be suitable microsensors in conjunction with Si fabrication technology.

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1356-1361
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• 2018

Replacing conventional Si diodes with SiC diodes in Si insulated gate bipolar transistor (IGBT) modules is advantageous as it can reduce power losses significantly. Also, the fast switching nature of the SiC diode will allow Si IGBTs to operate at their full high-switching-speed potential, which at present conventional Si diodes cannot do. In this work, the electrical test results for Si-IGBT/4HSiC-Schottky hybrid substrates (hybrid SiC substrates) are presented. These substrates are built for two voltage ratings, 1.7 kV and 3.3 kV. Comparisons of the 1.7 kV and the 3.3 kV Si-IGBT/Si-diode substrates (Si substrates) at room temperature ($20^{\circ}C$, RT) and high temperature ($H125^{\circ}C$, HT) have shown that the switching losses in hybrid SiC substrates are miniscule as compared to those in Si substrates but necessary steps are required to mitigate the ringing observed in the current waveforms. Also, the effect of design variations on the electrical performance of 1.7 kV, 50 A diodes is reported here. These variations are made in the active and termination regions of the device.

• 전자공학회논문지A
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• 제30A권7호
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• pp.38-46
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• 1993

Based on the close correlation between the optoelectronic and electrical characteristics of laser diodes, this paper is to present an exact model for electrical characteristics of laser diodes with bulk active layers so that the optoelectronic characteristics may be estimated from the electrical Characteristics. Among the considered models, the most exact model is shown to be one which uses the Fermi-Dirac integral and the bimolecular recombination and takes into account the energy-gap shrinkage with the injected carrier density.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1199-1202
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• 2007

The improvement of the electron injection is of critical importance for obtaining efficient and stable organic light-emitting diodes(OLEDs). Here, we report some of our recent results on the development of new cathode interlayer materials for OLEDs. Some of our new materials show performance superior to that of LiF.

• Journal of Information Display
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• 제9권2호
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• pp.14-17
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• 2008

A charge trapping host structure was developed to improve the light-emitting efficiency of green phosphorescent organic light-emitting diodes. N, N'-dicarbazolyl-3,5-benzene(mCP) and a spirobifluorene based triplet host(PHl) were co-deposited as hosts in the emitting layer and the device performance was examined according to the composition mCP and PH1. The results showed that the quantum efficiency could be improved by 30 % using a mixed host of mCP and PH1.

• 전기의세계
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• 제22권2호
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• pp.45-50
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• 1973

Amorphous semiconducting diodes from As Te Ge systm of which resitivity are 10$^{6}$ -10$^{8}$ .ohm.-cm order, are made and they exhibited several conducting states. A high conductivity, low conductivity and memory state are reported. Temperature dependency of the specimens are widerange. According to the procedure and cooling method, specimens are made easily or not. Threshold voltage of switching and memory diodes is in proportional to compositonal quantity of Arsenic. Threshold voltage is changed widely according to ambient temperature. Threshold voltage of #132 is 620V at 25.deg. C, 70V at 100.deg. C.

• Transactions on Electrical and Electronic Materials
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• 제6권3호
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• pp.97-100
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• 2005

Dynamic response of organic light-emitting diodes were analyzed in $ITO/Alq_3$(100 nm)/Al device structure with a variation of voltage an frequency. At low frequency region, complex impedance is mostly governed by resistive component, and at high frequency region by capacitive component. Also, we have evaluated resistance, capacitance and permittivity of devices.