• Transactions on Electrical and Electronic Materials
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• v.15 no.6
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• pp.324-327
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• 2014

Germanium (Ge) is a promising material for next generation nanoelectronics and multiple junction solar cells. This work investigated the electrical properties in Cu/p-type Ge Schottky diodes, using current-voltage (I-V) measurements. The Schottky barrier heights were 0.66, 0.59, and 0.70 eV from the forward ln(I)-V, Cheung, and Norde methods, respectively. The ideality factors were 1.92 and 1.78 from the forward ln(I)-V method and Cheung method, respectively. Such high ideality factor could be associated with the presence of an interfacial layer and interface states at the Cu/p-Ge interface. The reverse-biased current transport was dominated by the Poole-Frenkel emission rather than the Schottky emission.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.5
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• pp.360-366
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• 2020

Focused electron beams with high energy acceleration are versatile probes. Focused electron beams can be used for high-resolution imaging and multi-mode nanofabrication, in combination with, molecular precursor delivery, in an electron microscopy environment. A high degree of control with atomic-to-microscale resolution, a focused electron beam allows for precise engineering of a graphene-based field-effect transistor (FET). In this study, the effect of electron irradiation on a graphene FET was systematically investigated. A separate evaluation of the electron beam induced transport properties at the graphene channel and the graphene-metal contacts was conducted. This provided on-demand strategies for tuning transfer characteristics of graphene FETs by focused electron beam irradiation.

• Journal of information and communication convergence engineering
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• v.9 no.5
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• pp.583-586
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• 2011

In this paper, subthreshold swing characteristics have been presented for double-gate MOSFETs, using the analytical model based on series form of potential distribution. Subthreshold swing is very important factor for digital devices because of determination of ON and OFF. In general, subthreshold swings have to be under 100mV/dec. The channel length $L_g$ is varied from 30nm to 100nm, and channel thickness $t_{si}$ from 15 to 20nm according to channel length, and oxide thickness 5nm to investigate subthreshold swing. The doping of channel is fixed with $10^{16}cm^{-3}$ p-type. The results show good agreement with numerical simulations, confirming this model.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.12
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• pp.1057-1062
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• 2008

The ${\alpha}-In_2S_3:Co^{2+}$ single crystal with a good quality and stabilized property were gained successfully by the CTR(Chemical Transport Reaction)method. XRD analysis showed that the grown single crystals were cubic structure. The optical absorption spectra of ${\alpha}-In_2S_3:Co^{2+}$ single crystal showed impurity absorption peaks due to cobalt impurity. These impurity absorption pesks were assigned to the ligand transition between the split energy levels of $Co^{2+}$ ions sited in $T_d$ symmetry of these semiconductor host lattice.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.299-302
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• 1998

Electroluminescent(EL) devices based on organic materials have been of great interest due to their possible applications for large-area flat-panel displays. They are attractive because of multicolor emission low operation voltage. In this study, several Eu complexes such as Eu(TPB)$_3$(Phen) and Eu(TPB)$_3$(Bpy) were synthesized and the photoluminescence(PL) and electroluminescence (EL) characteristics of their thin films were investigated by fabricating the devices having a structure of glass substrate/ITO/TPD/Europium-complexs/Alq$_3$/Al, where aromatic diamine(TPD) was used as an hole transporting and Alq$_3$ was used as an electron transporting materials. It was found that the photoluminescence(PL) and electroluminescence(EL) characteristics of these Europium complexes were dependent upon the ligands coordinated to Europium 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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.171-174
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• 1995

Space charge formation in epoxy loaded with silica and calcium carbonate has been studied. The epoxy itself showed almost no charge at up to 40 kV/mm. The addition of fillers such as SiO$_2$and CaCO$_3$resulted in homocharge formation, which was attributed to the interfacial trapping of injected charge at epoxy/filler interfaces. The amount of charge showed a maximum at 20-40 parts per hundred resin above which the charge decreased gradually. This was tentatively attributed to the enhanced interconection of charge transport path by an increased filler content

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.10
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• pp.792-795
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• 2001

we present a electrical transport(resistivity, Hall effect) measurements in varying temperature ranges between 78K and 300K on HoSi$_2$ composites by hot-pressed sintering. It has been found that this sintered HoSi$_2$ has a orthorhombic structure, and lattices constant is a=9.8545$\AA$, b=7.7935$\AA$, c=7.8071$\AA$. The measured electrical resistivity is about 1.608$\Omega$ cm and carrier mobility is about 6.9$\times$10$^{1}$cm $^{2}$V.sec at low room temperature. The Hall effect shows a n-type conductivity in the sintered HoSi$_2$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.3
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• pp.199-205
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• 2005

Polycrystalline cadmium sulfide(CdS) thin films were deposited on glass substrate by chemical bath deposition(CBD) and vacuum evaporation (VE) techniques. VE-CdS films consisted primarily of hexagonal phase, whereas CBD CdS films containing primarily the cubic form. VE-grown films were shown to have better crystallinity than CBD-grown films. The grain size of the CBD films is smaller than the ones of VE films. VE-CdS films exhibited relatively high transmittance in the above-gap region and band gap compared with CBD films. However, CdTe solar cells with these low quality CBD-CdS layers yield higher and more stable characteristics. Current-voltage-temperature measurements showed that the current transport for both cells was controlled by both tunneling and interface recombination but the cells with CBD-CdS displayed less tunneling.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.554-557
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• 2001

In this work, we had synthesis the GaN powder by direct reaction between Ga and NH$_3$at the temperature range of 1000∼1150$^{\circ}C$, and investigated the reaction condition dependence of the GaN yield and some properties of GaN powder. The synthesized powder had Platelet and prismatic shape and showed hexagonal crystalline structure with the lattice constants of a= 3.1895 ${\AA}$, c= 5.18394 ${\AA}$, and the ratio of c/a = 1.6253. The GaN powder synthesis processes were examined based on the oxidation process of mater, and found as combined with mass transport process for the initial stage and diffusion-limited reaction for the extended reaction.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.12
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• pp.1039-1044
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• 2000

Breakdown voltage model and expertiments are compared for discharge cells of AC plasma display panel. In the model, discharge paths are assumed to be initial electric field lines and the one-dimensional continuity equation is applied to the charged particle transport at each field line. The comparisons are performed in the wide range of gas pressure (50-600torr), Xe partial pressure over total pressure (1-6%), sustain electrode gap(100-1000$\mu\textrm{m}$), wall height(130, 300$\mu\textrm{m}$), and voltage pulse width(2-6${\mu}$s). The presented breakdown voltage model well agree with experiments in the above wide range. The increase of breakdown voltage with the decrease of the width(L) of protruding electrode is also described by the model.