• Journal of the Korean Vacuum Society
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• v.17 no.4
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• pp.353-358
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• 2008

In order to increase extraction efficiency of AlGaInP-based vertical RED LEDs, chemical wet etching technique was produced by using a roughened surface with triangle-like morphology. A commonly used $H_3PO_4$-based solution was applied for chemical wet etching. The light extraction of AlGaInP LED was related to the n-side roughed surface morphology. The morphology of roughed surface is analyzed by the atomic force microscope (AFM). As a result, the roughed surface AlGaInP LED has a root-mean-square (RMS) roughness of 44 nm. The brightness shows 41% increase after roughening n-side surface, as compared to the ordinary flat surface LED.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.4
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• pp.49-55
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• 2004

This paper describes a 1550 nm multichannel source using Quatemary/quatemary multiple quantum well (MQW) InGaAsP/InGaAsP quantum confined Stark effect (QCSE) tuning for dense wavelength division multiplex (DWDM) systems with 140 ㎓ channel spacing and 32 nm channel selection bandwidth.

• Journal of the Microelectronics and Packaging Society
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• v.4 no.2
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• pp.71-78
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• 1997

본 논문에서는 InGaAsP 에피막에서 도핑 농도와 에피막의 미세조직구조가 photoluminescence (PL) 스펙트럼의 위치 및 형상에 어떤 영향을 미치는가를 연구하였고, 그 결과를 설명하기 위해 가능한 모델을 제시하였다. InGaAsP 에피막(발진파장 ~1.3$\mu$m) 을 액상증착법(liquid phase epitaxy, LPE)으로 성장하여 9K에서 PL측정을 했을 때 InGaAsP 활성층 내 Zn 억셉터의 유무에 따라 PL 피크의 위치가 최대 30nm (24meV)까지 shift하고 피크의 선폭도 넓어지는 현사을 발견하였다. 이와같은 피크 분산현상은 inGaAsP 에피막이 유기금속 기상증착법으로 성장되거나 Zn로 고농도로 도핑되거나 고온에서 어닐링 될 경우 대폭 감소하였다. 이를 설명하기 위해 여러 가지 모델을 설정하여 실험을 하였으며 이 중 InGaAsP 에피막의 미세조직구조 특히 Spinodal 분해에 의한 조성이 모듈레이션과 Zn의 상호작용의 관계가 이 현상을 설명하는 데 가장 적절하다는 것을 밝혔다.

• Journal of the Korean Vacuum Society
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• v.15 no.3
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• pp.294-300
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• 2006

We fabricated the distributed feedback (DFB) InP/InGaAs/InP grating structures on InP (100) substrates by metal-organic chemical vapor deposition, and their structural properties were investigated by atomic force microscopy and scanning electron microscopy. Self-assembled InAs/InAlGaAs quantum dots (QDs) were grown on the InP/InGaAs/InP grating structures by molecular beam epitaxy, and their optical properties were compared with InAs/InAlGaAs QDs without grating structure. The duty of the grating structures was about 30%. The PL peak position of InAs/InAlGaAs QDs grown on the grating structure was 1605 nm, which was red-shifted by 18 nm from that of the InAs/InAlGaAs QDs without grating structure. This indicates that the formation of InAs/InAlGaAs QDs was affected by the existence of the DFB grating structures.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.13-16
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• 2001

InP/InGaAs Heterojunction phototransistors(HPT's) with an optically transparent ITO emitter electrode were fabricated and characterized. At the same time, heterojuntion transistors(HBT's) having the same device layout were fabricated. By comparison with InP/InGaAs HBT's, the do characteristics of InP/InGaAs HPT's showed the similar electrical charateristics of HBT's. the model parameters of the device were extracted and compared.

• KSBB Journal
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• v.5 no.3
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• pp.247-253
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• 1990

These studies were carried out to obtain the transformant from carrot cells by using binary vector pGA472 with NPT II gene to confer kanamycin resistance in the plant cells. The binary vector pGA472 was mobilized from E. coli MC1000 into A. tumefaciens strains isolated in the Korea, C23-1. K29-1, and disarmed Ti-plasmid PC2760, and A28l using a tri-parental mating method with E. coli HB101/pRK2013. Transconjugants, C23-1/pGA472, K29-1/pGA472, PC2 760/pGA472 and A28l/pGA472 were obtaind on the minimum AB media containing tetracycline and kanamycin, were comfirmed to hold the Ti-plasmid and pGA472 binary vector on the 0.7% agarose gel. Transformed carrot calli were initiated on the MS media supplemented with l00$\mu\textrm{g}$/ml kanamycin and 250$\mu\textrm{g}$/ml carbenicillin after co-cultivation of carrot explant and transconjugant Agrobacteria. Selected callus was grown vigouousley for subculture on the medium containing 100$\mu\textrm{g}$/ml kanamycin, thus indication that the selected callus was transformed with NPT II gene.

• ETRI Journal
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• v.11 no.4
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• pp.84-97
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• 1989

The influence of Zn, Si and Te diffusion on the interdiffusion in $GaAs-Ga_1_-xIN_xAs_1__yP_y$and InP$Ga_1__xIn_xAs_1__yP_y$ heterostructures was studied. The heterostructures were grown by liquid phase epitaxy, and the impurity diffusion into the heterostructures was carried out using metal compound or element sources. The extent of interdiffusion for both group III and V atoms was observed by depth profiling of matrix elements with secondary ion mass spectrometry and Auger electron spectroscopy. Selective enhancement of cation interdiffusion was observed by the concurrent Zn diffusion in both the GaAs based-and InP based-crystals. In contrast to the Zn diffusion, the Si diffusion in the GaAs based-crystal and the Te diffusion in the InP based-crystal enhanced both cation and anion interdiffusion to the same extent. A kick-out mechanism is proposed to explain the selective enhancement of the cation interdiffusion due to Zn, and a single vacancy mechanism is proposed for the interdiffusion due to Si and Te.

• Journal of the Optical Society of Korea
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• v.11 no.3
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• pp.133-137
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• 2007

We compare electroabsorption modulators (EAMs) with multiple quantum wells (MQWs) based on InGaAs(P)/InP and InGa(Al)As/InAlAs material systems. We carefully choose the quantum-well structures so that the structures based on different material systems have similar band-offset energies and excition-peak wavelengths. Assuming the same light wavelength of $1.55{\mu}m$, we show the transfer functions of EAMs with each quantum-well structure and calculate the escape times of photogenerated charge carriers. As the heavy-hole escape time of the quantum well based on InGaAs(P)/InP is much longer than those of photogenerated charge carriers of InGa(Al)As/InAlAs, the EAM based on the InGa(Al)As/InAlAs material seems to be more suitable for high-optical-power operation.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.4
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• pp.143-148
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• 2019

We have successfully fabricated high aspect-ratio GaN-based nanowires on Si substrates using molecular beam epitaxy (MBE) system for high-efficiency hydrogen generation of photoelectrochemical water splitting. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) demonstrated that p-GaN:Mg and p-InGaN nanowires were grown vertically on the substrate with high density. Furthermore, it was also confirmed that the emission wavelength of p-InGaN nanowire can be adjusted from 552 nm to 590 nm. Such high-aspect ratio p-InGaN nanowire structure will be a solid foundation for the realization of ultrahigh-efficiency photoelectrochemical water splitting through sunlight.

• Electrical & Electronic Materials
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• v.7 no.4
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• pp.312-316
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• 1994

In this study, ln$_{1-x}$ Ga$_{x}$P alloy crystal which has different compositions were grown by the temperature gradient solution(TGS) method, and the properties of deep levels were measured in the temperature range of 9OK-450K. We find the four deep levels of E$_{1}$, E$_{2}$(248meV), E$_{3}$(386meV) and E$_{4}$(618meV) in GaP, which has composition of Ga in In$_{1-x}$ Ga$_{x}$P is one, and the trap densities of E$_{3}$ and E4 levels were 7.5*10$^{14}$ cm$^{-3}$ and 9*10$^{14}$ cm$^{-3}$ , respectively. A broad deep level spectra was revealed in In$_{1-x}$ Ga$_{x}$P whose composition of Ga, x, were 0.56 and 0.83, and the activation energy and trap densities were about 430meV and 6*10$^{14}$ cm$^{-3}$ , respectively.ectively.