• Journal of the Korean Ceramic Society
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• v.55 no.4
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• pp.325-336
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• 2018

Perovskite solar cells (PSCs) are a new class of photovoltaic devices, which have attracted significant attention due to their remarkable optoelectrical properties, including high absorption coefficients, high carrier mobilities, long carrier diffusion lengths, tunable bandgaps, low cost, and facile fabrication. PSCs have reached efficiencies of 22.70% and 18.36% on rigid fluorine-doped tin oxide and poly(ethylene terephthalate) substrates, respectively; these are comparable to those of single-crystal silicon and copper-indium-gallium-selenium solar cells. Over the past eight years, the photo conversion efficiency of PSCs has been significantly improved by device-architecture adjustments, and absorber and electron/hole transport layer optimization. Each layer is important for the performance of PSCs; hence, we discuss achievements in flexible perovskite solar cells (FPSCs), covering electron/hole-transport materials, electrode materials. We give a comprehensive overview of FPSCs and put forward suggestions for their further development.

• Transactions on Electrical and Electronic Materials
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• v.6 no.6
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• pp.280-283
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• 2005

The moving photocarrier grating (MPG) technique for the determination of the carrier mobilities and the recombination lifetime of $\alpha$-Se:As films has been studied. The electron and hole drift mobility and the recombination lifetime of $\alpha$-Se films with arsenic (As) additions have been obtained from measurement of the short circuit current density $j_{sc}$ as a function of grating velocity and spatial period. The hole mobility decreases due to defect density of hole traps when x exceeds 0.003, whereas the hole mobility increases for the case of low As addition (x$\le$0.003). We have found an increase in hole drift mobility and recombination lifetime, especially when As with (x = 0.003) is added into the $\alpha$-Se film.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.54.1-54.1
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• 2012

Recent significant development of organic electronics is worthy of notice for its practical application as well as fundamental understandings. Complementary-like logic circuit is a key factor to realize actual operating organic electronic devices since its advantages of low power dissipation, good noise margin and stable operations. In this reason, studies on ambipolar properties of organic materials which can act as either n-type or p-type are getting more attentions. Performances of ambipolar transistors vary a lot along its molecular structures and film properties. When properly fabricated, balanced hole and electron mobilities over 1 cm2/Vs were observed recently. Study of charge transport in ambipolar organic transistors to understand this high performance was carried out through charge modulation spectroscopy.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.524-526
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• 2009

The effects of In and Ga contents on characteristics of InGaZnO (IGZO) films grown by a sol-gel method and their thin film transistors (TFTs) have been investigated. Excess In incorporation into IGZO enhances the field effect mobilities of the TFTs due to the increase in conducting path ways, and decreases the grain size and the surface roughness of the films because more $InO_2^-$ ions induce cubic stacking faults with IGZO. Ga incorporation into results in decrease in carrier concentration of films and off-current of TFTs since Ga ion forms stronger chemical bonds with oxygen than Zn and In ions, acting as a carrier killer.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.174-178
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• 2007

A series of new oligomers were synthesized by Grignard reaction, the Suzuki coupling reaction, etc. The oligomers showed excellent TFT performance with mobilities higher than $0.5\;cm^2V^{-1}S^{-1}$ and on/off ratios higher than 5 $x10^5$. Their electronic and optical properties were investigated using many analysis methods, such as X-ray diffraction (XRD), UV-vis and photoluminescence spectroscopies.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.1
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• pp.56-62
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• 1992

The GaAs bulk crystals are grown by the Synthesis Solute Diffusion(SSD) method and its properties are investigated. The crystal growth rate at optimum condition is 0.28 cm/day and their temperature dependence is R(T) = 2.92 x 10S04T exp(-1.548eV/kS1BTT) [cmS02T/day.K]. Etch pits density distribution along radial direction is order of 10S04TcmS0-2T and 10S03TcmS0-2T at the edge and middle of the wafers, respectively, and it increased exponentially along vertical direction of ingot. Moreover,it is uniformly distributed as order of 10S03TcmS0-2T in radial direction of In doped GaAs. The carrier concentration and mobilities are measured to 0.34-2.1 x 10S016T cmS0-3T and 2.3-3.3x10S03T cmS02T/V.sec, respectively.

• YAKHAK HOEJI
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• v.27 no.4
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• pp.315-320
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• 1983

Ginseng proteins have been extracted and partially purified by the methods of ammonium sulfate fractionation, heat inactivation and Sephadex G-75 column chromatography. The final three fractions obtained (GI, GII and GIII) were subjected to paper chromatography and SDS-polyacrylamide gel electrophoresis. Molecular weights of polypeptide chains from each fraction were est-mated by the standard line obtained from the plot of electrophoretic mobilities against the logarithm of molecular weights of standard proteins. Results are as follows: 1) GI showed three protein spots and four polypeptides of which M.W. were 63,000, 60,000, 56,000, 51,000 and 34,200. 2) GII showed four protein spots and five polypeptides with their M.W. of 64,600, 56,000, 45,400, 35,800, end 25,200, 3) GIII showed three protein spots and four polypeptides with their M.W. of 66,000, 63,000, 56,000 and 22,000.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.378-381
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• 2001

The electron drift mobility of poly(4,4'-cyclohexylidenediphenyl carbonate)(PC-Z) doped with 3,5-dimethy-3,5-di-t-butylstilbenequinone(MBSQ), 3,5,3,5-tetra-t-butyl stilbenequinone(TMSQ) and 3,5,3,5-tetra-methyl stilbenequinone(TMSQ) was measured by the time-of-flight technique. The electric field and temperature dependences of the electron drift mobility were discussed with Poole-Frenkel, Arrhenius formulations and non-Arrhenius type of temperature dependence. It was assumed that the hopping sites were Gaussian distribution. Mobility and activation energy of MBSQ were increased with increasing dopant. However, mobilities and activation energy of TBSQ and TMSQ were increased and decreased, respectively.

• Korean Journal of Psychosomatic Medicine
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• v.3 no.2
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• pp.197-206
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• 1995

Obesity is a major nutritional problem in the developed countries. The prevalence of obesity may range from 10 to 50 per rent or mort of adult population and it may be increasing tendency. Many efforts have been made to understand the pathogenesis of obesity, but except a few metabolic obesities in the most of obese patients, the mechanisms are not understood. The treatment modalities of obesity, ranging from dietary and pubilc health intervention through the pharmacological and surgical therapy, have been developed and tested. In the obese patients mortalities and mobilities are significantly increased than non obese subjects due to hypertension, diabetics, and other problems. There are four possible mechanisms by which energy balance might be altered to enhance metabolic efficiency. futile metabolic pathway, alteration of protein rum over, alteration in sodium-potassium ATPase and alteration in uncoupled oxidation in brown adipose tissue are considered as possible mechanisms. Low calory and very low calory diets are recommended as a dietary program. Several pharmacological agent such as benzphetamine, fenfluramine, mazindol and fluoxetin are currently popular drugs for the treatment of obesity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.190-190
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• 2007

To improved the conjugation between $SiO_2$ and P3HT active layer, P3HT/POSS conjugated polymers were synthesised and used as the active layers of organic TFT's. We achieved the field-effect mobilities in the saturation region ${\sim}1.19{\times}10^{-3}\;[cm^2/v{\cdot}sec]$ and on/off ratio ${\sim}2.51{\times}10^2$. These values are higher than ones of the P3HT-based OTFTs. The results also demonstrated the off-current decrease.