• 한국전기전자재료학회논문지
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• 제32권3호
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• pp.196-200
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• 2019

In this study, photoluminescence (PL) analysis was performed to evaluate the optical properties of commercial ZnO substrates. Particular attention was paid to the bound exciton (BX) luminescence, which is usually the strongest emission intensity of commercial substrates. At 15 K, PL analysis revealed that the BX peak due to donor-type impurities (donor-bound-exciton; DX) dominated, while two-electron satellite (TES) emission, donor-accepter pair (DAP) emission, and LO-phonon replica emission were also observed. The impurity concentration of the ZnO substrate was determined to be $10^{15}$ to $10^{16}/cm^3$ by examination of the temperature variation of DAP, while the half width and intensity change of the luminescence revealed that the temperature change of BX can be interpreted almost the same as the analysis of free-exciton emission.

• 한국전기전자재료학회논문지
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• 제30권1호
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• pp.42-47
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• 2017

In this study, the physical and optical properties of $ZnS:Mn^{2+}$ Quantum Dot prepared by wet-process condition with Mn/Zn ratio was valuated. The powder characteristics and optical behavior were investigated through XRD, TEM and Photo spectrometer exicted by various UV light source. We found the main peak of ZnS (111) was shifted by 0.8 degree to low angle position with increasing stirring energy from 200 RPM to 600 RPM, which is thought to be the increase of lattice defects during wet process. The photo luminescence at 600 RPM shows also higher blue intensity which is well correlated with XRD results. With increasing Mn/Zn ratio, the PL intensity become higher and shifed by 8.5nm to right side, by the increment of substitutional $Mn^{2+}$ ions.

• 한국전기전자재료학회논문지
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• 제19권8호
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• pp.749-753
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• 2006

The $ZnGa_2O_4$ phosphor thick films were fabricated using a screen printing method on Si(100) substrates at various sintering temperatures. The XRD patterns show that the $ZnGa_2O_4$ thick films have a (311) main peak and a spinel structure with increasing sintering temperatures. The particle sizes of $ZnGa_2O_4$ phosphor were about 100 nm and the thickness of $ZnGa_2O_4$ thick film was $10{\mu}m$. The CL and PL properties of $ZnGa_2O_4$ showed main peak of 420nm and maximum intensity at the sintering temperature of $900^{\circ}C$. These results indicate that $ZnGa_2O_4$ phosphor thick films hold promise for displays such as plasma display panel and field emission display.

• 한국산학기술학회논문지
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• 제3권3호
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• pp.161-165
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• 2002

게르마늄첨가 다성분계 산화물 유리를 제조하여 자외선(UV) 조사에 따른 유리의 미세 구조변화를 PL(photo-luminescence)과 ESR(electron spin resonance)을 이용하여 관찰하였다. 게르마늄 첨가량이 증가함에 따라 PL방사량은 증가하였으며, UV 조사 후에는 처음과 반대되는 광혹화 현상으로 감소하는 현상을 나타냈다. UV조사로 변화된 특성은 열처리를 통하여 회복이 가능하였으며, ESR 측정에서도 PL결과와 같은 광혹화 현상(phodarkenine effect)과 열표백화 현상(thermal bleaching effect)이 확인되었다. 또한, XRD 분석을 통하여 이러한 현상이 비정질 상은 그대로 유지하는 미세구조 변화임을 알 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.424-425
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• 2006

Zinc sulfide is a well-known host material of phosphor emitting different radiations dependent on different doping impurities of metallic ion. It emits green, blue, orange-yellow or white colors by doping with activators such as copper, silver, manganese and so on. In this study, manganese, copper and chlorine doped ZnS phosphor (ZnS:Mn,Cu,Cl) was synthesized by solid-state reaction method. The optical properties were investigated according to different concentrations of sulfur and activators used during the synthesis process.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2002년도 춘계 기술심포지움 논문집
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• pp.177-179
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• 2002

본 연구는 Ag와 Ce이 함유된 유리를 용융법에 의해 제조하였으며, 355nm Nd:YAG 펄스 레이저를 조사하였을 때의 광학적 특성과 열처리과정에서 발생하는 결정화의 변화과정에 대해 평가하였다. Ce이 함유된 유리는 환원 분위기에서 제조되었으며, Optical Absorption을 통하여 Ce$^{3+}$ 이온이 존재하는 유리의 흡수대역을 관찰하고자 하였다. Photo Luminescence(PL) 측정을 통해 Ce$^{3+}$ 이 존재하고 있음을 확인하였으며, Ce$^{3+}$ 이온의 5d$\longrightarrow$4f 전이를 관찰하였다. 이와같이 Ce$^{3+}$ 가 함유된 유리는 레이저를 조사하였을 경우 PL의 강도가 저하됨을 확인하였다. 열처리과정에서 발생하는 결정화현상을 고찰하기 위해 열분석을 실시하였으며, 레이저조사된 유리에서 최대결정화온도가 감소함을 관찰하였다.

• 한국진공학회지
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• 제15권3호
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• pp.308-313
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• 2006

서로 다른 성장조건 하에서 자발형성 InAs 양자점 (quantum dot, QD)을 제작하고. 그 특성을 photoluminescence (PL) 로 분석하였다. 비교적 높은 기판온도에서 성장된 QD 시료들의 PL 스펙트럼에서 분명한 차이를 나타내는 double-peak이 관측되었다. 온도 및 여기광 출력의존성 (temperature- and excitation power dependence) PL을 이용하여 그 double-peak이 서로 다른 크기분포를 가지는 두개의 InAs QD집단에서의 기저발광 (Eo) 에 의한 peak 임을 알 수 있었다. 게다가 이중크기분포에서 InAs 두께변화는 서로 대립되는 두 QD집단에서 QD 수의 변화를 초래한다는 것 또한 증명하였다.

• 한국세라믹학회지
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• 제55권1호
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• pp.55-60
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• 2018

In this study, quantum dots composed of $Mn^{2+}$ doped ZnS core and ZnS shell were synthesized using MPA precursor at room temperature. The ZnS: Mn/ZnS quantum dots were prepared by varying the content of MPA in the synthesis of ZnS shells. XRD, Photo-Luminescence (PL), XPS and TEM were used to characterize the properties of the ZnS: Mn/ZnS quantum dots. As a result of PL measurement using UV excitation light at 365 nm, the PL intensity was found to greatly increase when MPA was added at 15 ml, compared to the case with no MPA; the PL peaks shifted from 603 nm to 598 nm. A UV sensor was fabricated by using a sputtering process to form a Pt pattern and placing a QD on the Pt pattern. To verify the characteristics of the sensor, we measured the electrical properties via irradiation with UV, Red, Green, and Blue light. As a result, there were no reactions for the R, G, and B light, but an energy of 3.39 eV was produced with UV light irradiation. For the sensor using ZnS: Mn/ZnS quantum dots, the maximum current (A) value decreased from $4.00{\times}10^{-11}$ A to $2.62{\times}10^{-12}$ A with increasing of the MPA content. As the MPA content increases, the PL intensity improves but the electrical current value dropped because of the electron confinement effect of the core-shell.

• 한국전기전자재료학회논문지
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• 제37권1호
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• pp.68-73
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• 2024

In this study, the praseodymium-doped yttrium phosphate (YPO₄:Pr³⁺) powder, which is well known for its high luminescent efficiency, and long life in the UV range, was synthesized with various content ratios of Pr₆O₁₁ and calcination temperature. Crystal structure and luminescent properties of various phosphor powders based on different concentrations and calcination conditions were characterized by XRD (X-Ray Diffraction) and PL (photoluminescence) spectrometers. From the XRD analysis, the structure of YPO₄:Pr³⁺ which is calcinated at 1,200℃ was stable tetragonal phase and crystal size was calculated about 25 nm by Scherrer equation. PL emission of YPO₄:Pr³⁺ with a different content ratio of Pr₆O₁₁ by excitation λ_exc=250 nm shows that 0.75 mol% phosphor powder has maximum PL intensity and PL decreases with the increase of the ratio of Pr₆O₁₁ up to 1.25 mol% which is caused by changes of crystallinity of phosphor powders. With increasing dopant ratio, photo-luminescence Emission decreases due to Concentration quenching, which is commonly observed in phosphors. Currently, 0.75 mol% is considered the optimal doping concentration. A hybrid ultraviolet-emitting device incorporating YPO₄:Pr³⁺ fluorescent material with plasma discharge was fabricated to enhance UV germicidal effects while minimizing ozone generation. UV emission from the plasma discharge device was shown at about 200 nm and 350 nm which caused additional emission of the regions of 250 nm, 315 nm, and 370 nm from the YPO₄:Pr³⁺ phosphor.

• 한국광학회:학술대회논문집
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• 한국광학회 2002년도 하계학술발표회
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• pp.134-135
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• 2002

Sm$^{2＋}$가 도핑된 불화물 결정은 실온에서 영구적 스펙트럼 홀 생성이 나타나며, 이러한 실온에서의 영구적 스펙트럼 홀 생성은 새로운 광 메모리의 개발에 매우 중요하므로 많은 관심을 받고 있다. 본 연구에서는 Sm$^{2＋}$가 도핑된 10Al$_2$O$_3$.90SiO$_2$ 박막을 제조하여 SEM 및 발광 스펙트럼(Photo-Luminescence; PL)을 측정함으로서 제조된 박막의 구조적, 광학적 특성을 조사하였다. (중략)