• 한국진공학회지
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• 제18권5호
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• pp.365-371
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• 2009

크기가 다른 양자점 (chirped 양자점) 구조에 대하여 전기발광 (Electroluminescence, EL) 특성과 광발광 (Photoluminescence, PL) 특성을 측정하고 비교 분석하였다. PL 특성에서는 양자점의 기저준위에 의한 피이크가 우세하게 나타난 반면, EL 특성에서는 여기준위에 의한 특성이 우세하게 나타났다. 이와 같은 특성비교로부터 기저준위도 EL 특성에 영향을 미칠 수 있도록 chirped 양자점 구조를 설계하면 파장대역폭이 더욱 넓은 고휘도 발광소자 개발이 가능할 것임을 제안하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 제5회 영호남 학술대회 논문집
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• pp.93-93
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• 2003

Photoluminescence(PL) properties of Silicon nanocrystals (nc-Si) as a function of temperature is reported to consider the mechanism of PL. Nc-Si has been made by $Si^+$ ion-implantation into thermal $SiO_2$ and subsequent annealing. And after gold had been diffused at the same samples above, the resultant PL spectra has been compared to the PL spectra from the non-gold doped nc-Si. PL peak energy variation from nc-Si is same with the variation of energy bandgap of bulk silicon as temperature changes from 6 K to room temperature. This result may mean nc-Si is still indirect transition material like bulk silicon. Gold doped nc-Si reveals short peak wavelength of PL spectrum than gold undoped one. PL peak shift through gold doing process shows clearly the PL mechanism is not from defect or interface states. PL intensity increases from 6K to a certain temperature and then decrease to room temperature. This characteristic with temperature shows that phonon have a role for the luminescence as theory explains that electron and hole can be recombined radiatively by phonon's assist in nc-Si, which is almost impossible in bulk silicon. Therefore luminescence is observed in nc-Si constructed less than a few of unit cell and the peak energy of luminescence can be higher than the bulk bandgap energy by the bandgap widening effect occurs in nanostructure.

• 한국재료학회지
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• 제19권7호
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• pp.356-361
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• 2009

The optical characterization of self-assembled InAs/AlAs Quantum Dots(QD) grown by MBE(Molecular Beam Epitaxy) was investigated by using Photoluminescence(PL) spectroscopy. The influence of thin AlAs barrier on QDs were carried out by utilizing a pumping beam that has lower energy than that of the AlAs barrier. This provides the evidence for the tunneling of carriers from the GaAs layer, which results in a strong QD intensity compared to the GaAs at the 16 K PL spectrum. The presence of two QDs signals were found to be associated with the ground-states transitions from QDs with a bimodal size distribution made by the excitation power-dependent PL. From the temperature-dependent PL, the rapid red shift of the peak emission that was related to the QD2 from the increasing temperature was attributed to the coherence between the QDs of bimodal size distribution. A red shift of the PL peak of QDs emission and the reduction of the FWHM(Full Width at Half Maximum) were observed when the annealing temperatures ranged from 500 $^{\circ}C$ to 750 $^{\circ}C$, which indicates that the interdiffusion between the dots and the capping layer was caused by an improvement in the uniformity size of the QDs.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.1042-1044
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• 2003

The photoluminescence (PL) properties are studied for a new phosphor $BaZr(BO_{3})_{2}$ doped with $Eu^{3+}$ activator ion. The excitation spectrum shows strong absorption in the vacuum ultraviolet (VUV) region with an absorption band edge at 200 nm. The PL spectrum shows the strongest emission at 615 nm corresponding to the electric dipole $^{5}D_{0}\;{\rightarrow}\;^{7}F_{2}$ transition of $Eu^{3+}$, which results in a good color purity.

• 한국전기전자재료학회논문지
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• 제14권2호
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• pp.99-103
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• 2001

We present a detailed of the interband transitions of InAs/GaAs self-organized quantum dots(QDs) based on surface photovoltage(SPV), photoreflactance(PR) and photoluminescence(PL) spectroscopies. At room temperature, interband absorption transitions of QDs have been observed by using SPV spectrum, which clearly exhibits three well-resolved absorption transitions of QDs have been observed by using SPV spectrum, which clearly exhibits three well-resolved absorption peaks. The absorption line shape is Gaussian-like. Furthermore, the corresponding interband transitions are also observed in PR and PL experiments at 77K.

• 한국전기전자재료학회논문지
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• 제13권9호
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• pp.776-780
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• 2000

ZnGa$_2$O$_4$thin films were prepared on Si(100) wafer in terms of RF power, substrate temperatures and Ar/O$_2$flow rate by RF Magnetron Sputtering. Photoluminescence(PL) measurement was employed to observe the emission spectra of ZnGa$_2$O$_4$films. The influences of various deposition parameters on the properties of grown films were studied. The optimum substrate deposition temperature for luminous characteristics was about 50$0^{\circ}C$ in this investigation. PL spectrum of ZnGa$_2$O$_4$ thin films showed broad band luminescence spectrum.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.145-148
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• 2000

In contrast to the $\pi$ -conjugated polymers which typically absorb light only in the visible spectral region, the $\sigma$-conjugated polymers can be used as efficient material absorbing light in the UV region. In this work, the electronic and optical properties of I$_2$-doped $\sigma$ -conjugated poly (methyl-phenylsilylene) (PMPSi) polymer were investigated. DC conductivity up to 1.2$\times$10$^{-4}$ S/cm was obtained by I$_2$-doping. In UV/Vis absorbance spectrum, a new peak was observed near 370 nm, which was explained by polaron model. The photoluminescence (PL) intensity decreased with increasing degree of I$_2$-doping, and the Infrared (IR) spectrum analysis revealed that the dopants are not directly coupled to the polymer, but effect motions of the methyl and phenyl groups.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.316-319
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• 2000

By RF magnetron sputtering ZnGa$_2$O$_4$thin films were prepared on Si(100) wafer in terms of RF power, substrate temperatures and Ar/O$_2$flow rate. Crystallographic orientation was characterized by x-ray diffraction(XRD). Surface morphology and microstructure were observed by scanning electron microscope(SEM). Photoluminescence(PL) measurement was employed to observe the emission spectra of ZnGa$_2$O$_4$films. The influences of various deposition parameters on the properties of grown films were studied. PL spectrum of ZnGa$_2$O$_4$thin films showed broad band luminescence spectrum.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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• pp.60-61
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• 2005

Electrodes were fabricated on a single ZnO nanowire by photolithography process, metal evaporation, and lift-off. The slow photoresponses of the ZnO nanowire under the continuous illumination of 325nm-wavelength light (corresponding to above-bandgap excitation) indicate that the traps related to oxygen vacancy disturb the flow of electron in ZnO nanowire. The photoresponse and PL spectra were measured, and observed that the excitonic band in the PL spectrum was absent in the photoresponse.

• 센서학회지
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• 제11권3호
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• pp.183-190
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• 2002

실리콘 기판 위에 형성한 열산화막에 실리콘이온을 주입하고 열처리를 수행한 후, 광루미네센스(photoluminescence:PL) 스펙트럼을 조사하였다. 실리콘 이온도즈의 변화와 열처리 온도의 변화에 따른 PL스펙트럼을 조사하고, 이를 TEM과 XRD 데이터와 비교하여 분석한 결과, 광루미네센스 특성은 산화막내의 실리콘 나노결정으로부터 기인함을 알 수 있었다. 또 산화막을 1분 간격으로 습식 식각하면서 매 식각 시마다 PL스펙트럼을 관측하여 그 변화를 조사하였다. 이러한 실험을 통하여 산화막내에 분포하고 있는 실리콘 나노결정의 크기와 그 수가 PL피크 파장과 강도에 직접적으로 영향을 줌을 알 수 있었다.