• Current Photovoltaic Research
• /
• v.4 no.2
• /
• pp.64-67
• /
• 2016

We investigated the influences of Ag nanoparticle (NP) arrays and surface nanohole (NH) patterns on the optical characteristics of 10-${\mu}m$-thick c-Si wafers using finite-difference time-domain (FDTD) simulations. In particular, we comparatively studied the plasmonic effects of both monomer arrays (MA) and heptamer arrays (HA) consisting of identical Ag NPs. HA improved the optical absorption of the c-Si wafers in much wider wavelength range than MA, with the help of hybridized plasmon modes. The light trapping capability of the NH array pattern is superior to that of the Ag plasmonic NPs. We also found that the addition of the Ag HA on the wafers with surface NH patterns further enhanced optical absorption: the expected short-circuit current density was as high as $34.96mA/cm^2$.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.13 no.6
• /
• pp.279-283
• /
• 2003

In this study, ZnTe : S single crystal thin films substituted by sulfur were grown on GaAs (100) substrates by hot-wall epitaxy. The photoluminescence (PL) characteristics of ZnTe : S single crystal thin films was measured to investigate the effects due to sulfur atoms in the ZnTe layer. The Peak of 2.339 eV identified as the isoelectronic center was observed in low temperature PL spectrum, but PL spectra which the origin had not been well-explained were not observed. Temperature dependence of PL intensities of the light hole free exciton was explained by extrinsic self-trapping. Besides it is reported that the emission lines near absorption edge at room temperature were observed.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.16 no.4
• /
• pp.180-186
• /
• 2023

Positive bias temperature instability (PBTI) degradation of n⁺ and p⁺ poly-Si gate high-voltage(HV) SiO2 dielectric nMOSFETs was investigated. Unlike the expectation that degradation of n⁺/nMOSFET will be greater than p⁺/nMOSFET owing to the oxide electric field caused by the gate material difference, the magnitude of the PBTI degradation was greater for the p⁺/nMOSFET than for the n⁺/nMOSFET. To analyze the cause, the interface state and oxide charge were extracted for each case, respectively. Also, the carrier injection and trapping mechanism were analyzed using the carrier separation method. As a result, it has been verified that hole injection and trapping by the p⁺ poly-Si gate accelerates the degradation of p⁺/nMOSFET. The carrier injection and trapping processes of the n⁺ and p⁺ poly-Si gate high-voltage nMOSFETs in PBTI are detailed in this paper.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.17 no.10
• /
• pp.898-906
• /
• 2005

The present study has been conducted to investigate convective heat/mass transfer in the cooling passage with bleed holes. The rotating square channel has 40.0 mm hydraulic diameter and the bleed holes on the leading surface of the channel. The hole diameter of bleed hole is 4.5mm and its spacing is ( p/d:4.9) about five times of hole diameter. Exit mass flow rate through bleed holes is $10\%$ of the main mass flow rate and relation number is changed form 0.0 to 0.4. A naphthalene sublimation technique is employed to determine the detailed local heat transfer coefficients using the heat and mass transfer analogy The cooling performance is influenced by exit mass flow rate through bleed holes and Coriolis force of rotating channel for fixed Reynolds number. The heat transfer on the leading surface is decreased due to Coriolis force. However the total heat transfer is enhanced around holes on the leading surface because of trapping flow by bleeding.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.17 no.10
• /
• pp.907-913
• /
• 2005

The present study has been conducted to investigate convective heat/mass transfer in the cooling passage with bleed holes. The rotating square channel has 40.0 mm hydraulic diameter and the bleed holes on the leading surface of the channel. The hole diameter of bleed hole is 4.5mm and its spacing is ( p/d:4.9) about five times of hole diameter. Exit mass flow rate through bleed holes is $0\%,\;10\%\;and\;20\%$ of the main mass flow rate respectively. rotation number is fixed 0.2. A naphthalene sublimation technique is employed to determine the detailed local heat transfer coefficients using the heat and mass transfer analogy. The cooling performance is influenced by exit mass flow rate through bleed holes and Coriolis force of rotating channel for fixed Reynolds number. The heat transfer on the leading surface is decreased due to Coriolis force. However the total heat transfer is enhanced around holes on the leading surface because of trapping flow by bleeding.

• Proceedings of the KIEE Conference
• /
• 1987.11a
• /
• pp.257-259
• /
• 1987

The photoelectronic properties of CdTe films sintered with various amounts of $CdCl_2$ and $CuCl_2$ have been investigated by measurements of dark electrical resistivity, photocurrent, thermoelectric power, optical transmission and by observation of microstructure. The grain size and optical transmission of sintered CdTe films increase with increasing amount of $CdCl_2$ indicating that $CdCl_2$ acts as a sintering aid. The photoconductivity gain(A-$cm^2/W$) increases and resistivity($\Omega$-cm) decreases with increasing amount of $CuCl_2$ up to 100ppm due to the occurance of Cu-doping during sintering. The dark resistivity could be reduced farther by post heat treatments. The dark resistivity was still high($10^3{\Omega}$-cm) so that the accurate determination of the hole concentration by Hall measurement or by thermoelectric power measurement was not possible. From the analysis of electrical activation energy, however it can be concluded that the hole concentration is less than $10^{14}/cm^3$ and all grains are depleted of carrier by the trapping centers at grain boundaries.

• Proceedings of the IEEK Conference
• /
• 2004.06b
• /
• pp.327-330
• /
• 2004

It is shown that the hot carrier degradation due to enhanced hot holes trapping dominates PMOSFETs lifetime both in thin and thick devices. Moreover, it is found that in 0.13 ${\mu}m$ CMOSFET the PMOS lifetime under CHC (Channel Hot Carrier) stress is lower than the NMOSFET lifetime under DAHC (Drain Avalanche Hot Carrier) stress. Therefore. the interface trap generation due to enhanced hot hole injection will become a dominant degradation factor. In case of thick MOSFET, the degradation by hot carrier is confirmed using charge pumping current method and highly necessary to enhance overall device lifetime or circuit lifetime in upcoming nano-scale CMOS technology.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08b
• /
• pp.1454-1456
• /
• 2007

The electrical and the optical properties of blue organic light-emitting devices (OLEDs) with a multiple emitting layer (EML) acting as electron and hole trapping layers were investigated. While the luminance efficiency of the OLEDs with a multiple EML was very stable, regardless of variations in the applied voltage.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08b
• /
• pp.1301-1304
• /
• 2007

We have investigated degradation of short channel n-type poly-Si TFTs with LDD under high gate and drain voltage stress due to self-heating. We have found that the threshold voltage of short channel TFT is shifted to negative direction on the selfheating stress, whereas the threshold voltage of long channel is moved to positive direction.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.41 no.2
• /
• pp.185-191
• /
• 1992

In this paper, it is attempted to distinguish the charged particles and to judge the polarity by the use of Thermally Stimulated Current(TSC) and Temperature Gradient Thermally Stimulated Surface Potential Measurement(TG-TSSP)with experimental insulation material XLPE-EVA for power cables which is made by blending cross-linked polyethylene(XLPE) and ethylene-vinylacetate copolymer(EVA). In addition, it is performed to investigate the effect of EVA blending. From the experimental results, it is known that for the case of XLPE-EVA blended experimental material, the generation of space charged electric field is not obtained in the high temperature region due to the obatruction of the injection of trapping carrier by the electron and the positive hole.