• 통합자연과학논문집
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• 제3권4호
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• pp.197-201
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• 2010

Dihydrotetraphenylgermole has been synthesized from the reduction of dichlorotetraphenylgermole with lithiumaluminiumhydride. UV-Vis absorption and photoluminescence was measured by using UV-Vis and fluorescence spectroscopy. Nanoparticles of dihydrotetraphenylsilole were synthesized from the mixture solution of water and THF. Photoluminescence behavior of organogermanium nanoparticle was investigated at various water fractions. Critical fraction of water to form organogermanium nanoparticles was 60%. Photoluminescence intensity of organogermanium nanoparticle was increased as the concentration of organogermanium nanocolloids increased. Photoluminescence efficiency of organogermanium nanoparticle at 90% water fraction increased about 100 times compared to that of molecular state.

• 한국세라믹학회지
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• 제41권5호
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• pp.359-363
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• 2004

Photoluminescence excitation (PLE) spectroscopy studies were performed for anodically etched porous Zn, which exhibited a PL in the blue/violet spectral range peaking at 420 nm (2.95 eV), and oxidzed porous Zn at 380$^{\circ}C$ for 10 min and 12 h. A broad absorption band was observed at 4.07 eV (305 nm), 3.49 (355 nm) for anodically etched porous Zn. In contrast, both the oxidized porous Zn and sintered ZnO exhibited an almost identical one broad absorption band at 3.85 eV (322 nm), when PLE spectra were measured at 378 nm (3.28 eV). The oxidized porous Zn and sintered ZnO, which displayed both UV and green luminescence band, showed an additional absorption band at 389 nm (3.19 eV) and 467 nm (2.66 eV). In contrast, no significant absorption band was detected for a 10-min oxidized porous Zn, which only displayed one UV luminescence void of deep-level luminescence. These absorption bands determined by PLE studies enabled a clear understanding of an emission mechanism for the UV and green luminescence from ZnO.

• Transactions on Electrical and Electronic Materials
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• 제1권3호
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• pp.6-9
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• 2000

Selectively excited photoluminescence(PL) spectroscopy has been carried out on the ~1540 nm $^{4}$I$_{13}$ 3/ to $^{4}$I/wub 15/2/ emissions of the multiple Er$^{3+}$ centers observed in Er-implante undoped and Mg-doped GAN at temperatures ranging from 6K to 295K. The temperature dependence of the Er$^{3+}$ PL spectra selectively excited by below -gap light demonstrates different quenching rates for the distinct Er$^{3+}$ centers, and indicates that the PL spectra with the most rapid thermal quenching rats do not contribute to the room temperature, above-p-pumped Er$^{3+}$ spectrum. In addition, selective PL spectroscopy has ben carried out on the Er$^{3+}$ emission in Er-implanted undoped and Mg-doped GaN at temperatures ranging 6K to 295K. The results indicate that the previously reported enhancement of the violet-pumped centers contribution to the low temperature above excited Er$^{3+}$ PL in Mg-doped GaN is also evident at room temperature.temperature.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.418-419
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• 2006

We investigate the influence of the ambient gas during thermal annealing on the photoluminescence (PL) properties of europium-silicate thin films. The films were fabricated on substrates by using a radio-frequency magnetron sputtering method and subsequent rapid thermal annealing (RTA). The mechanism for the formation of the europium silicates during the annealing process was investigated by using X-ray diffraction (XRD) spectroscopy, Auger electron spectroscopy (AES) and transmission electron microscopy (TEM). A series of narrow PL spectra from $Eu^{3+}$ ions was observed from the film annealed in $O_2$ ambient. Broad PL spectra associated with $Eu^{2+}$ ions, with a maximum intensity at 600 nm and a FWHM of 110 nm, were observed from the thin film annealed at $1000^{\circ}C$ in $N_2$ ambient.

• 한국진공학회지
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• 제17권2호
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• pp.170-174
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• 2008

고립된 탄소나노튜브를 얻기 위해 계면활성제 Sodium Dodecyl Sulfate(SDS) 수용액에 단층 탄소나노튜브 분말을 넣어 초음파 처리를 하는 과정 중에 발생하는 물성 변화를 라만과 Photoluminescence를 통하여 연구하였다. 단층 탄소나노튜브(SWCNT) radial breathing mode(RBM)의 라만신호 세기의 변화는 SWCNT의 chirality에 따라 서로 다른 경향성을 보이고 초음파 처리 시간에 영향을 받음을 확인하였다. 또한 동일한 농도의 계면활성제에 담긴 SWCNT의 농도가 커지면 G-band 라만 진동수가 작아지면서 Photoluminescence 세기가 증가하는 현상을 관측하였다.

• 한국재료학회지
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• 제28권2호
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• pp.124-128
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• 2018

N-type porous silicon (PS) layers and thermally oxidized PS layers have been characterized by various measuring techniques such as photoluminescence (PL), Raman spectroscopy, IR, HRSEM and transmittance measurements. The top surface of PS layer shows a stronger photoluminescence peak than its bottom part, and this is ascribed to the difference in number of fine silicon particles of 2~3 nm in diameter. Observed characteristics of PL spectra are explained in terms of microstructures in the n-type PS layers. Common features for both p-type and n-type PS layers are as follows: the parts which can emit visible photoluminescence are not amorphous, but crystalline, and such parts are composed of nanocrystallites of several nm's whose orientations are slightly different from Si substrate, and such fine silicon particles absorb much hydrogen atoms near the surfaces. Light emission is strongly dependent on such fine silicon particles. Photoluminescence is due to charge carrier confinement in such three dimensional structure (sponge-like structure). Characteristics of visible light emission from n-type PS can be explained in terms of modification of band structure accompanied by bandgap widening and localized levels in bandstructure. It is also shown that hydrogen and oxygen atoms existing on residual silicon parts play an important role on emission stability.

• 한국전기전자재료학회논문지
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• 제16권2호
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• pp.89-96
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• 2003

Photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopy have been performed at 6 K on the 1540 nm $^4$I$\_$(13/2)/\longrightarrow$^4$I$\_$(15/2)/ emission of Er$\^$+3/ in in situ Er-doped GaN The PL and PLE spectra of in situ Er-doped GaN are compared with those of Er-implanted GaN in this study. The lineshapes of the broad PLE absorption bands and the broad PL bands in the spectra of the in situ Er-doped GaN are similar to those in Er-doped glass rather than in the Er-implanted GaN. The PL spectra of this in situ Er-doped GaN are independent of excitation wavelength and their features are significantly different from the site-selective PL spectra of the Er-implanted GaN. These PL and PLE studies reveal that a single type of Er$\^$3+/ sites is present in the in situ Er-doped GaN and these Er sites are different from those observed in the Er-implanted GaN. In addition, the comparison of the PL single strength illustrates that the excitation of Er$\^$3+/ sites through the energy absorption of defects in Er-implanted GaN.

• 한국응용과학기술학회지
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• 제31권3호
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• pp.337-344
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• 2014

이 논문은 온도차에 따라 변화되는 이온성 액체와 낮은 밴드갭을 갖는 고분자인 poly(2-heptadecyl-4-vinylthieno[3,4-d]thiazole)(PHVTT) 간의 상호작용 및 고분자의 거동을 조사하였다. 이온성 액체는 methyl imidazolium chloride([MIM]Cl), butyl methyl imidazolium chloride([BMIM]Cl), tri-butyl methyl ammonium methyl sulfate([TBMA][ $MeSO_4$])를 사용하였으며, 21, 28, 32, $37^{\circ}C$로 온도를 변화시키며 상호작용의 변화를 UV-vis spectroscopy, FT-IR spectroscopy, photoluminescence spectroscopy를 통해 확인한 결과 이온성 액체인 [MIM]Cl, [TBMA][$MeSO_4$]와 PHVTT의 상호작용은 점차 약해짐을 확인할 수 있었지만, [BMIM]Cl은 온도 변화에 따른 상호작용의 변화를 보이지 않았다.

• Journal of the Optical Society of Korea
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• 제16권1호
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• pp.76-79
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• 2012

$Tb_3Al_5O_{12}:Ce$ (TAG:Ce) thin films were successfully deposited by a pulsed laser ablation method on a quartz substrate, and low-temperature post-annealing effects on luminescent properties were investigated in detail. TAG:Ce thin films were analyzed by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy. The as-deposited films were amorphous, and post-annealing above $700^{\circ}C$ was required for crystallization. The post-annealed TAG:Ce thin films showed strong and broad emission bands around 542 nm and excitations at 451 nm, which all corresponded to transitions between the 4f ground level to the $5d^1$ excited levels of Ce ion.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.424.2-424.2
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• 2014

Ag-modified BiOX (X=Cl, Br and I) nanoplates were synthesized by an ion-exchange reaction. We examined the fundamental properties by scanning electron microscopy (SEM), electron transmission microscopy (TEM), X-ray diffraction, UV-visible absorption, Fourier-transform infrared and photoluminescence spectroscopy. The adsorption and photocatalytic performances of the catalysts were tested with dyes under UV and visible light. A chemical scavenger method was employed to test the roles of active species (${\cdot}OH$, ${\cdot}O2-$ and h+) and understand photodegradation mechanism. Photoluminescence spectroscopy was used to examine ${\cdot}OH$ radical formation using terephthalic acid during photoirradiation.