Joo Ijin

Abstract The solubility of hydrogen sulphide and carbon dioxide, respectively, in 2.5 and 5.0 N aqueous monoethanolamine solutions has been determined at temperatures of 40°C and 100°C. Partial pressures of CO 2 ranged from 0.1 to 1000 psia, while partial pressures of H 2 S ranged from 0.3 to 650 psia. The results have been used, together with literature data, to calculate enthalpies of solution.

The effects of the substrate bias voltage and the deposition temperature on the electrical characteristics and the 1/f noise of TiNx/n-Si Schottky diodes fabricated by reactive magnetron sputtering are investigated. As the substrate bias voltage varies from −40 to −100 V, the ideality factor of the diodes remain almost unchanged whereas the noise intensity as a function of the current shows a shift parallel by about one order of magnitude. At low current levels, the noise intensity is proportion

Abstract The solubility of mixtures of carbon dioxide and hydrogen sulphide in a 2.5 N monoethanolamine solution has been determined at temperatures of 40°C and 100°C. Partial pressures of CO 2 ranged from 0.7 to 5630 kPa, while partial pressures of H 2 S ranged from 0.7 to 3780 kPa. The present results extend the published data on this system which were limited to partial pressures below 200 kPa. The results have been compared with two methods of prediction based upon a thermodynamic model.

The growth of high quality CdTe epitaxial films on p-InSb(111) by a simple method of temperature gradient vapor transport deposition was carried out to investigate the possibility of the existence of a two-dimensional electron gas with high mobility at CdTe/InSb heterointerfaces. From the x-ray diffraction analysis, the grown layer was found to be a CdTe epitaxial film. Photoluminescence measurements at 15 K showed that a CdTe film grown on InSb(111) in the temperature range between 180 and 280

We report the photovoltaic properties of the donor–acceptor composite system of poly (p-phenylenevinylene) (PPV) and viologen. We observed the significant enhancement of photocurrent with increasing the doping ratio of viologen. The maximum photocurrent of viologen-doped PPV was nine times as high as that of the pristine PPV. The maximum quantum yield and photosensitivity are 13% (electron/photon) and 0.05 A/W, respectively, at low bias voltage (−2 V). The increase of photocurrent is explained w

Polycrystalline silicon thin-film transistors show a 1/fγ (with γ<1) low frequency noise behavior. The 1/fγ noise is explained by emission and trapping processes of carriers between trapping states located within an energy range of kT around the Fermi level and the exponential tail states. We have derived a simple relationship between the frequency index γ of the noise spectrum and the energy distribution parameter of the tail states. From the experimental noise data, the theoretical mode

We compared the structural and optical properties of InAs∕GaAs quantum dots grown by migration enhanced epitaxy, with and without arsenic, during indium deposition. The uniformity and size of the quantum dots are enhanced in a sample without arsenic. As a result, narrower and longer wavelength photoluminescence is observed in this sample. Furthermore, the thickness of the wetting layers is reduced by ∼20% in the sample without arsenic, and this result agrees well with the speculation that metall

Low-frequency noise measurements have been carried out in platinum silicide Schottky diodes on n-type silicon in the forward conduction regime and with the forward current IF as a parameter. The power spectral density of the current fluctuations shows a 1/f behavior and is proportional to IFβ (with 1<β⩽2). The experimental noise data have been successfully explained by an existing model of the random walk of electrons via the interface states, modified by taking into account the Schottky

In this article, we present an in-depth study of the effects of the structural and optical properties of InAs “dots in an In0.2Ga0.8As well” (DWELL) and InAs “dots in an asymmetric In0.2Ga0.8As well” (asym. DWELL) grown by migration-enhanced molecular beam epitaxy. The energy spacing (ΔE1) between the ground-state and the first-excited-state transitions increases from 66 meV for the DWELL to 73 meV for the asym. DWELL. These results are consistent with ΔE1 measured by photoluminescence excitatio

Time resolved photoluminescence (PL) characteristics of a SiN cap disordered GaAs/AlGaAs multiple quantum well (MQW) structure exhibit a decrease in carrier lifetime in conjunction with an increase in quantum well disordering (QWD) as the SiN capping layer thickness is increased. The decrease in carrier lifetime is attributed to enhanced carrier trapping due to the defects introduced during dielectric cap quantum well disordering and the relaxation of the momentum conservation during radiative r

Strain effects on sizes and emission energies of ZnSe∕ZnS quantum dots (QDs) have been investigated. The initial strain in the ZnSe QD layer was altered by adjusting the thickness of the ZnS buffer. Consistent blueshifts of the ground-state emission from 4 monolayer ZnSe QDs were observed with increasing the thickness of the ZnS buffer from 20 to 40nm. Atomic-force microscopy revealed that the blueshifts are due to a continuous QD size reduction. We estimated the emission energy as a function of