GaAlAs/GaAs DHLD의 結晶成長과 光電特性

吳煥述 건국대학교 1982 學術誌 Vol.26 No.2

The properties of Al0.3Ga0.7As/GaAs double heterostructure Laser diode operating by at wavelengths in the 0.847㎛ by Liquid phase epitaxy(LPE) grown layer are described. This device exhibit good electrical and optical confinement. The theoretical liquid and solid phase diagram for the LPE of AlGaAs ternary alloys has been described based on the thermodynamic equilibrium condition. The growth rates of GaAs and Al0.3Ga0.7As are ∼1㎛/℃, ∼0.5㎛/℃ respectively. The threshold current density increases with temperature for diode made from material near the band gap crossover composition. And the peak energy of the emission spectra measured on grown Al0.3Ga0.7As/GaAs LD are found to be 1.46eV(8470℃) and 1.83eV(6770Å) in the case EL (Electro Luminescent) and PL (Photo Luminescent) at 77˚K. For sufficiently narrow active layers, emission is usually single longitudinal mode oscillation and linear. CW light output power up to∼10 mW per facet have been observed at 77˚K.

적색형광색소 첨가에 의한 유기발광소자의 전기적 및 광학적 특성분석

오환술 건국대학교 산업기술연구원 2001 건국기술연구논문지 Vol.26 No.-

Red emission organic electroluminescent devices was fabricated by fluorescence dyes(DCM1 and Nile Red) doping into the Alq3 upon the ITO which was coated on glass. Two types of device were employed which type I was ITO/TPD/Alq3:DCMl/Al and type II was ITO/TPD/Alq3:Nile Red/Al structure. The dye concentration was variable 15~60 wt% for type I and 10~50wt% for type II. The peak omission wavelength of device I, II, III of type I was respectively 605nm, 611nm, 623nm. and turn-on voltage were 2~4V and driving voltage were 6V. The peak emission wavelength of device I, II, III of type II was respectively 621nm, 626nm, 637nm. Device I, II of type II had a driving voltage 6~8V but device III, IV had more than 11V. We obtained higher efficiency and natural red emission from type II than type I due to energy transfer mechanism. Finally we obtained emission luminescence 110 cd/m2 at 11V with device II of type II.

CSP 構造 GaAs-(Ga,Al)As 半導體레이저의 特性

吳煥述 건국대학교 1987 學術誌 Vol.31 No.2

A built-in refractive index waveguide structure is provided simply by growing Double Heterostructure (DH) layers on a grooved substrate. This structure is called Channeled-Substrate-Planar(CSP) injection laser. Undesirable nonlinear "kink" effect in light output vs. current characteristics of stripe geometry DH injection lasers are significiently reduced by stabilizing the transverse modes along the junction plane. Room temperature pulsed-threshold-current are in the range 150∼300mA with efficiency up to 35%.

光通信을 위한 GaAs-(Ga, Al)As DH LED의 周波數 應答의 最適化

吳煥述 건국대학교 부설 산업기술연구소 1983 논문집 Vol.8 No.-

A three layered ??/??/?? Double heterostructure light-emitting diode(DH LED) has been used to measure Optical Outputs, Spectra, and fundamental electrical characteristics in thin GaAs Substrates Prepared by liquid phase epitaxy(LPE). The cutoff frequency of LED is investigated as functions of design parameters, such as hole concentration of the active layer, thickness of the layer, and injected current density. The cutoff frequency increases with increasing the hole concentration and injection current density, and with decreasing the active layer thickness. The data presented in this paper by setting the recombination constant B to be ??. The hole concentration is optimized to be ?? for Ge doped active layer.

CPS-DH 構造 半導體 레이저 발진모우드의 안정화

吳煥述 건국대학교 부설 산업기술연구소 1987 논문집 Vol.12 No.-

The light leakage into the GaAs Substrate outside the Channel is shown to provide effective refractive index and loss differences, which function to stabilize the transverse mode in the junction plane. Observed light output vs. Current characteristics and far-field mode patterns in the lasers justify the theoretical model. Stable fundamental mode oscillation is achieved up to 2 ?? for a channel width of 2.8㎛, ??, t=0.3㎛.

초고속용 Delta-Doped GaAs FET 소자 제작

오환술 건국대학교 1992 學術誌 Vol.36 No.2

We investigate delta-FET and delta-doping characteristics for GaAs layer growth by Atmospheric Pressure Metal Organic Chemical Vapor Deposition(AP-MOCVD). The delta-FET structure was succesfully grown in the temperatures of 700∼750℃, which is comparable with the device fabricated the Molecular Beam Epitaxy (MBE). The two-dimensional electron gas formation in the delta-FET structure were evidenced through spike shape of C-V pronto, high mobility of Hall measurement. Delta-FET haying a gate length of 1㎛, 2㎛ and a gate width of 150㎛ have been Fabricated. The characteristics of the delta-FET can be summarized as (1) carrier density of 3.2 × 1018cm-3, (2) external transconductance of 45 mS/mm, (3) maximum saturated drain current of 235 mA/mm, (4) -11V breakdown voltage of the schottky gate, (5) contact resistance of 6 Ω-mm.

DPVBi/Rubrene 구조를 사용한 2-파장 방식의 백색유기발광소자의 광학적ㆍ전기적 특성에 관한 연구

오환술,조재영,최성진,강명구,윤석범 한국전기전자재료학회 2004 전기전자재료학회논문지 Vol.17 No.2

The white-light-emitting organic LED(OLED) with two-wavelength was fabricated using the DPVBi of blue emitting material and a series of orange color fluorescent dye(Rubrene) by vacuum evaporation processes. The basic structure of white-light-emitting OLED was ITO/NPB(150$\AA$)/DPVBi/Rubrene/BCP(100$\AA$)/Alq$_3$(150$\AA$)/Al(600$\AA$). We analyzed the fabricated device through the changes of the DPVBi and Rubrene layer's thickness. We obtained the white-light-emitting OLED with white color light and the CIE coordinate of the device was (0.29, 0.33) at applied voltage of 13V when the thickness of DPVBi layer was 210$\AA$ and the thickness of Rubrene layer was 180$\AA$. At a current of 100㎃/$\textrm{cm}^2$, the quantum efficiency was 0.35% and at a voltage of 20V, it was 0.405%.

광통신용 GaAs/(Ga, Al)As DH-LED의 최적 주파수 응용에 대한 연구

오환술,김영권 대한전자공학회 1984 전자공학회지 Vol.21 No.3

In this paper, we have used symmetrical GaAs/(Ga, Al) As DH-LED as a model for the optimization of frequency response which is the most important design parameter of the optical communication-LED. And optimum design parameters have been chosen to improve performance factors of the DH-LED by computer simulation. This is for the purpose of systematic consideration of the interrelation of the physical parameters such as impurity concentration of the active layer, thickness of the active layer, minority carrier lifetime, space charge capacitance and injected current density. 본 논문은 광통신용 광원의 가장 중요한 설계변수인 주파수응답의 최적화를 위하여 대칭 CaAs/(Ca, Al)As DH-LED를 모델로 채택하여 다이오드의 설계변수들인 활성층의 불순물농도, 활성층폭, 소수캐리어수명, 금지대폭, 굴절률, 공간전하용량, 주입전류밀도 등의 물리적 제인자들의 백호관계를 체계적으로 정립하여 컴퓨터 시뮬레이션에 의한 최적설계변수치들을 설정하는데 그 목적이 있다.

A Study on the Fabrication and An Analysis of the Characteristics of a Red Organic Light-Emitting Device with a Inorganic Multi-Metal Layer

오환술,강성종 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.6

An IMML(Inorganic metal multi-layer) was used as a cathode in an OLES(organic light -emitting diode) to reduce the reflectance of the ITO(Indium tin oxide) and to increase the contrast ratio. The device structure was ITO/α-NPD/Alq3:DCJTB/Alq3/ IMML/Al. Alq3 and DCJTB(4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7,-tetramethyljuloidyl-9-ethyl)-4H-pyran) as host material for red emission and red emitting guest material individually. The IMML was made of a three dierent layers: a chrome layer (100 A), chrome doped with silicon oxide (Cr : SiO : 50 % : 50 %, 350 A) and a thick aluminum layer (1500 Å). The aluminum layer was the actual electrode. The red OLED device with an IMML had a reflectance of 7.46 % and the reflectances of a normal OLED with and without polarizer were 4.58 %, an 46 % respectively, in the visible range from 380 nm to 780 nm. The brightness of the OLED with IMML at 11 V was 1,120 cd/m2 and that of a normal OLED with polarizer was 1,175 cd/m2. An IMML(Inorganic metal multi-layer) was used as a cathode in an OLES(organic light -emitting diode) to reduce the reflectance of the ITO(Indium tin oxide) and to increase the contrast ratio. The device structure was ITO/α-NPD/Alq3:DCJTB/Alq3/ IMML/Al. Alq3 and DCJTB(4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7,-tetramethyljuloidyl-9-ethyl)-4H-pyran) as host material for red emission and red emitting guest material individually. The IMML was made of a three dierent layers: a chrome layer (100 A), chrome doped with silicon oxide (Cr : SiO : 50 % : 50 %, 350 A) and a thick aluminum layer (1500 Å). The aluminum layer was the actual electrode. The red OLED device with an IMML had a reflectance of 7.46 % and the reflectances of a normal OLED with and without polarizer were 4.58 %, an 46 % respectively, in the visible range from 380 nm to 780 nm. The brightness of the OLED with IMML at 11 V was 1,120 cd/m2 and that of a normal OLED with polarizer was 1,175 cd/m2.

ARRAY MODE CHARACTERISTICS OF CHANNELED SUBSTRATE-PLANAR PHASE ARRAYS

오환술,J.K.Butler 대한전자공학회 1986 대한전자공학회 학술대회 Vol.1986 No.1