• 전기의세계
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• v.26 no.5
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• pp.83-89
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• 1977

This paper described the minority carrier lifetime in Si epitaxial layer, and also the voltage (V) versus current (I) characteristics of high resistivity Si epitaxial layer0substrate junction. The measured lifetime in Si epi-layer was much shorter than in bulk, and the temperature dependence of lifetime was found to agree well with Shockley-Read model of recombination which applies to high resistivity n-type materials. The V-I curve showed; an ohmic region (I.var.V), a sublinear region (I.var.V$^{1}$2/), a space charge limited current region (I.var.V$^{2}$), and finally a negative resistance region. We investigated these phenomena by the theory of the relaxation semiconductor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.1
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• pp.8-12
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• 2002

In this paper, we studied a flat fluorescent lamp with high luminance for LCD backlighting. The lamps have simple structures with ITO glass, insulator layer, phosphor layer, electrode layer and gas gap. The firing voltage was decreased with increasing the frequency. It was considered that this tendency was resulted from the space charge effect due to Xe and Ar positive ions trapped in gas gap. Decrease of uniform voltage at higher drive frequency is due to the remaining space charges which are produced by preceding period. As a result, luminance of 2700[cd/m$^2$] and maximum luminous efficiency of 51[m/W] were obtained with luminance uniformity of 96[%] in operation(700[V$\_$rms/], 80[kHz].

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.534-537
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• 2002

We have studied conduction mechanism that is interpreted in terms of space charge limited current (SCLC) region and tunneling region. The OLEDs are based on the molecular compounds, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD) as a hole transport, tris (8- hydroxyquinolinoline) aluminum(III) $(Alq_3)$ as an electron injection and transport and emitting later, copper phthalocyanine (CuPc) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and poly(vinylcarbazole) (PVK) as a buffer layer respectively. Al was used as cathode. We manufactured reference structure that has in ITO/TPD/$Alq_3$/Al. Buffer layer effects were compared to reference structure. And we have analyzed out luminance efficiency-voltage characteristics in ITO/Buffer layer/TPD/$Alq_3$/Al with buffer-layer materials.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.05a
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• pp.87-89
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• 1994

The effects of low molecular weight components of LDPE and sample molding condition were investigated to find the orgins for heterocharge in LDPE without any addtives. Low molecular weight chains of LDPE encourages the formation of heterocharge by being charged and migrating the counter electrode. The formation of heteroohage in LDPE was also effected by sample preparation process and the kind of a moling film. When PET film is used as a molding layer, the carbonyl, which may lead to increase the heterocharge, formed at surface of LDPE.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04b
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• pp.114-117
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• 2002

We have studied the dependence of current-voltage characteristics of Organic Light Emitting Diodes(OLEDs) on temperature-dependent variation. The OLEDs have been based on the molecular compounds. N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1, 1'- biphenyl-4, 4'-diamine (TPD) as a hole transport. tris(8-hydroxyquinolinoline) aluminum (III) ($Alq_3$) as an electron transport and Poly(3,4-ethylenedioxythiophene) (PEDOT:PSS) as a buffer layer. The current-voltage characteristics were measured in the temperature range of 10K and 300K. A conduction mechanism in OLEDs has been interpreted in terms of space-charge-limited current(SCLC) and tunneling region.Ā᐀會Ā᐀衅?⨀頱岒ᄀĀ저會Ā저?⨀⡌ឫഀĀ᐀會Ā᐀㡆?⨀쁌ឫഀĀ᐀會Ā᐀遆?⨀郞ග瀀ꀏ會Ā?⨀〲岒ऀĀ᐀會Ā᐀䁇?⨀젲岒Ā㰀會Ā㰀顇?⨀끩Ā㈀會Ā㈀?⨀䡪ഀĀ᐀會Ā᐀䡈?⨀Ā᐀會Ā᐀ꁈ?⨀硫Ā저會Ā저?⨀샟ගऀĀ저會Ā저偉?⨀栰岒ഀĀ저會Ā저ꡉ?⨀1岒ഀĀ저會Ā저J?⨀惝ග؀Ā؀會Ā؀塊?⨀ග䈀Ā切

• Journal of information and communication convergence engineering
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• v.17 no.2
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• pp.161-165
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• 2019

In this study, zinc tin oxide (ZTO) thin-film transistors are researched to observe the correlation between the barrier potential and electrical properties. Although much research has been conducted on the electronic radiation from Schottky contacts in semiconductor devices, research on electronic radiation that occurs at voltages above the threshold voltage is lacking. Furthermore, the current phenomena occurring below the threshold voltage need to be studied. Bidirectional transistors exhibit current flows below the threshold voltage, and studying the characteristics of these currents can help understand the problems associated with leakage current. A factor that affects the stability of bidirectional transistors is the potential barrier to the Schottky contact. It has been confirmed that Schottky contacts increase the efficiency of the element in semiconductor devices, by cutting off the leakage current, and that the recombination at the PN junction is closely related to the Schottky contacts. The bidirectional characteristics of the transistors are controlled by the space-charge limiting currents generated by the barrier potentials of the SiOC insulated film. Space-charge limiting currents caused by the tunneling phenomenon or quantum effect are new conduction mechanisms in semiconductors, and are different from the leakage current.

• Korean Chemical Engineering Research
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• v.58 no.2
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• pp.319-324
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• 2020

Electroconvective instability is a non-linear transport phenomenon which can be found in ion-selective transport system such as electrodialysis, Galvanic cell and electrolytic cell. The instability is triggered by the fluctuation of space charge layer in adjacent of ion-selective surface, leading to increase of mass transport rate. Thus, in the aspect of mass transport, the instability has an important meaning. Although recent experimental techniques have opened up an avenue to direct visualize the instability, fundamental investigations have been conducted in limited area due to several experimental limitations. In this work, the electroconvective instability under potentiostatic mode was solved by numerical method in order to demonstrate correlation between current-time curve and the instability behavior. By rigorous time-resolved analysis, the transition behaviors can be divided into three stages; formation of space charge layer - growth of electroconvective instability - steady state. Furthermore, scaling laws of transition time were numerically obtained according to applied voltage as well.

• Korean Journal of Optics and Photonics
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• v.25 no.2
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• pp.95-101
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• 2014

When voltage is applied on the metal layer of a surface plasmon resonance (SPR) sensor, electric field excitation causes charge accumulation on the metal surface. This alters not only the optical properties of the metal but also the SPR angle. In this study we investigate this effectby performing experiments using solutions of various pH values, and we obtain the relation between total surface charge and SPR angle. The curves for the various pH conditions become coincident. We compare our results to those from an earlier space charge layer (SCL) model, and suggest a modified SCL model which explains our result well. This result will be useful in applications of SPR sensors, and in studying the optical properties of thin metal layers.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.3
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• pp.60-65
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• 1984

In this paper, we have used symmetrical GaAs/(Ga, Al) As DH-LED as a model for the optimization of frequency response which is the most important design parameter of the optical communication-LED. And optimum design parameters have been chosen to improve performance factors of the DH-LED by computer simulation. This is for the purpose of systematic consideration of the interrelation of the physical parameters such as impurity concentration of the active layer, thickness of the active layer, minority carrier lifetime, space charge capacitance and injected current density.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.37-38
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• 2000

The ZnS:Tb thin-film electroluminescent devices were grown by atomic layer deposition with utilizing single-layer aluminum oxide and/or multilayered tantalum aluminum oxide, $Ta_xAl_yO$, as upper and lower insulating layers. These devices were investigated in terms of the luminescent and electrical characteristics. From this analysis, the devices using the $Ta_xAl_yO$ instead of $Al_2O_3$ were observed to have a lower threshold voltage for emission due to the higher relative dielectric constant of $Ta_xAl_yO$ insulators than that of the $Al_2O_3$ device. And there was a large amount of dynamic space charge generation in the phosphor of the device with the $Ta_xAl_yO$ insulators seemingly due to electron multiplication such as trap ionization.