• 전기전자학회논문지
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• 제21권3호
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• pp.288-296
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• 2017

The enhancement of photoluminescence of Au-$TiO_2$ nanoparticles by surface plasmon resonance has been studied extensively by experiment in recent years. For the purpose of optimizing the photoluminescence property of Au-$TiO_2$ nanoparticles, the manufacturing parameters related to the Au nanoparticles and $TiO_2$ nanoparticles need to be considered. In this paper, Drude model and Maier's effective volume method are used to analyze the variation of the metal nanoparticle radius, separation between metal nanoparticle and dielectric molecule, and total absorption cross-section with original radiative efficiency on the photoluminescence property of Au-$TiO_2$ nanoparticles. The results show that to obtain the optimized enhancement factor for photoluminescence process, the size of Au nanoparticle is about 13 - 20 nm, the separation between Au nanoparticle and $TiO_2$ molecule is about 5 -15 nm, the total absorption cross-section of $TiO_2$ molecules is about $1-100nm^2$ and the original radiative efficiency of $TiO_2$ molecule is weak about 0.001- 0.1. With these fabrication parameters, the photoluminescence property of Au-$TiO_2$ nanoparticles can be enhanced several thousand times compared to traditional $TiO_2$ nanoparticles.

• 통합자연과학논문집
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• 제3권2호
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• pp.107-111
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• 2010

Silicon-containing ${\pi}$-conjugated compounds, especially silacyclopentadienes (siloles), have emerged as a new class of electroactive materials with good electron transport properties in OLEDs. 9,9'-spiro-9-silabifluorene compound as well as its starting material 2,2'-dibromobiphenyl have been synthesized with higher yields. Spirosilabifluorene is expected to be an efficient host material for the blue-light emitting diodes. 9,9'-spiro-9-silabifluorene, 1,1-dichloro-1-silafluorene, and 1,1-dimethyl-1-silafluorene were characterized by $^1H$-NMR, UV/Vis and photoluminescence spectroscopy.

• 조명전기설비학회논문지
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• 제24권4호
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• pp.10-16
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• 2010

본 논문에서는 ZnO와 $Ga_2O_3$ 분말을 1 : 1의 mole비로 혼합하고 여기에 Mn을 첨가하여 Ar 주입 상태와 진공 상태에서 조성된 $ZnGa_2O_4$ : Mn을 합성하였다. 제작된 $ZnGa_2O_4$ : Mn의 발광 스펙트럼 관찰을 하여 산소의 성분 변화가 발광 특성에 미치는 영향을 설명하였다. 또한 저온의 Photoluminescence(PL) 스펙트럼으로부터 Mn의 site symmetry가 발광 스펙트럼에 미치는 영향을 설명하였다.

• 한국세라믹학회지
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• 제45권3호
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• pp.146-149
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• 2008

Strontium-substituted $Sr_{1-x}Ba_xAl_2O_4:Eu^{2+},\;Dy^{3+}$ compositions were prepared by the solid state synthesis method. These compositions were characterized for their phase, crystallinity and morphology using powder x-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Photoluminescence properties were investigated by measuring excitation spectra, emission spectra and decay time for varying Ba/Sr concentrations. Photoluminescence results show higher luminescence and long decay time for $Sr_{1-x}Ba_xAl_2O_4:Eu^{2+},\;Dy^{3+}$(x=0). This is probably due to the influence of the 5d electron states of $Eu^{2+}$ in the crystal field. Long persistence was observed for these compositions due to $Dy^{3+}$ co-doping.

• 한국자기학회지
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• 제17권1호
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• pp.1-5
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• 2007

Rutile 구조를 가진 반강자성체 $MnF_2$와 단결정 $MnF_2(1.5%\;EuF_3)$의 Infra-Red 흡수 스펙트럼과 Photoluminescence 측정을 했다. 측정된 Data의 분석을 통해서 $EuF_3$가 1.5% 첨가된 $MnF_2$와 순수한 $MnF_2$의 광학적 성질의 차이를 밝혀내고, Eu의 첨가에 의해 나오는 PL은 $Eu^{3+}$의 f-d 전이에 의한 것임을 확인했다.

• 통합자연과학논문집
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• 제2권1호
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• pp.28-31
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• 2009

We describe the synthesis and characterization of silicon nanoparticles prepared by the soluton reduction of SiCl4. These reactions produce Si nanoparticles with surfaces that are covalently terminated. The resultant organic derivatized Si nanoparticles as well as a probable distribution of Water-soluble Si nanoparticles are observed and characterized by photoluminescence(PL) spectroscopy. This work focuses originally on the organic- and water-soluble silicon nanoparticles in terms of the photoluminescence. Further this work displays probably the first layout of hydrogen terminated Si nanoparticles synthesized in solution at room temperature.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2007년도 추계학술발표대회 및
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• pp.90.1-90.1
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• 2007

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.620-620
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• 2013

When $MoS_2$ is thinned to single layer (1L), photoluminescence (PL) quantum yield drastically increases due to emergence of direct band gap. A recent theory predicts that the electronic structure of 1L $MoS_2$ is very sensitive to its lattice constants. We investigated the response of 1L $MoS_2$ to biaxial tensile strain using spatially resolved PL and Raman spectroscopy. Changes in the lattice constants were monitored by the Raman frequency of the in-plane ($E^1{_2g}$) mode. Systematic correlations between PL and Ramanspectral features, revealed in the preliminary results, will be further tested with samples on other substrates and against thermal stress. The results will also be discussed in regard to the theory which predicts that 1L $MoS_2$ becomes an indirect semiconductor at small tensile strain and turns metallic when further extended.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3319-3325
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• 2014

Eu(III)-doped $CeO_2$ nanorods were prepared by a co-precipitation method at room temperature, and their photoluminescence profiles were examined with different Eu(III)-doping concentrations and thermal annealing temperatures. Scanning electron microscopy, X-ray diffraction crystallography and UV-Vis absorption spectroscopy were employed to examine the morphology, crystal structure and photon absorption profiles of the nanorods, respectively. Additionally, their 2D and 3D-photoluminescence profile maps were obtained to fully understand the photoluminescence mechanism. We found that the magnetic dipole $^5D_0{\rightarrow}^7F_1$ and the electric dipole $^5D_0{\rightarrow}^7F_2$ transitions of Eu(III) were highly dependent on the doping concentration, annealing temperature and excitation wavelength, which was explained by the presence of different Eu(III)-doping sites (with and without an inversion center) in the $CeO_2$ host with a cubic crystal structure.

• 한국진공학회지
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• 제2권3호
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• pp.294-298
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• 1993

CuGaSe2 단결정을 고순도(99.9999%)의 Cu, Se 원소를 화학조성비로 칭량한 후 Se을 3mole% 과잉으로 첨가하여 합성된 ingot를 사용하여 iodine(99.9999%)을 수송매체로 한 화학수송법으로 성장시켰다. 성장된 단결정은 검정색을 띠고 있었으며, 10K에서 optical energy gap이 1.755eV로 주어졌다. Ar-ion laser로 여기시켜 측정한 photoluminescence(PL) 스펙트럼으로부터 1.667eV, 1.085eV, 1.025eV에 위치한 세 개의 PL peak를 얻었다. Thermally stimulated current(TSC) 측정에서 0.660eV, 0.720eV의 deep donor level을 관측하였으며, PL peak intensity의 thermal quenching으로 구한 activation energy는 0.010eV이었다. CuGaSe2 단결정에서 PL mechanism은 edge emission 및 donor-acceptor pair recombination임을 규명했다.