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Journal of the Korean Chemical Society (JKCS)

ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 61, Number 4
JKCSEZ 61(4)
August 20, 2017 
 
Title
 Color Tuning of a Mn4+ Doped Phosphor : Sr1−xBaxGe4O9:Mn4+ 0.005 (0.00 ≤ x ≤ 1.00)

Mn4+ 도핑된 형광체, Sr1−xBaxGe4O9:Mn4+ 0.005 (0.00 ≤ x ≤ 1.00)의 Color Tuning
Author
 Woon Bae Park

박운배
Keywords
 발광 다이오드, 형광체, 밀도함수 이론, 밴드 갭, X선 회절 , LED, Phosphor, DFT, Band gap, XRD
Abstract
 백색 LED 기술이 발달함에 따라 적색 형광체는 산업 및 학계에서 점차 중요성이 커지고 있으며, 시장에서 수요는 꾸준 히 증가했다. 적색 형광체는 고효율 및 고연색의 LED 조명에 사용된다. 그러나 Eu2+ 활성제를 사용한 적색 형광체는 4f-5d 전이 로 발생하는 녹색 또는 황색 스펙트럼 영역에서의 강한 재흡수로 인해 백색 LED 칩에서 색상 변경 및 발광 강도의 저하를 유발 했다. 이러한 단점이 없고 연색성 지수(CRI)를 더 향상할 수 있는 Mn4+ 도핑된 형광체가 현재 매우 중요하다. 그러나 Mn4+ 도핑 된 형광체는 2Eg→ 4A2 전이로 인하여 발광 파장이 모체에 따라 결정된다는 단점이 있다. 본 연구는 동일구조의 SrGe4O9와 BaGe4O9 모체를 합성하여 Sr1−xBaxGe4O9:Mn4+ 0.005 (x = 0, 0.25, 0.5, 0.75 and 1)를 얻었다. 이로 인해 LED 기술의 다양한 색상 조정이 가능 해졌다.

Along with the progress of white LED technology, red phosphors have become increasingly important in industry and academia, and a more specific demand has steadily increased in the market. Red phosphors are used in high efficiency and high rendering LED lightings. However, using red phosphors with Eu2+ activators caused color rewarming and reduced emission intensity in white LED chips due to strong reabsorption in the green or yellow wavelength range caused by the 4f-5d transition. Mn4+ doped phosphors which have no such drawbacks and which can further improve the color rendering index (CRI) are now of great interest. However, Mn4+-doped phosphors have a disadvantage in that the emission wavelength is determined depending on the host due to the 2Eg→4A2 transition. In this study, the SrO-BaO-GeO2 solid-solution was selected, and Sr1−xBaxGe4O9:Mn4+ 0.005 (0 ≤ x ≤ 1) phosphors were synthesized and characterized. This led to a versatile color tuning in LED technology.

Page
 163 - 167
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