합성공정이 Ba2SiO4:Eu2+ 형광체 분말의 합성과 발광특성에 미치는 영향
Effects of the Preparation Process on the Synthesis and the Luminescence of Ba2SiO4:Eu2+ Phosphor Powders
0
조회
0
다운로드
0
인용
0
참고문헌
키워드
초록
졸-겔법 및 졸-겔법과 연소법을 함께 사용한 하이브리드법으로 각각 얻어진 건식 젤을 열처리하여 Ba2SiO4:Eu2+ (B2S:Eu2+) 분말을 합성하였으며, 이들 공정에 따른 구조 및 발광 특성 변화를 조사하였다. Si 공급원으로서는 tetraethyl orthosilicate (TEOS)를 사용하였다. 졸-겔법에 의한 건식 젤로 하소 과정 없이 합성한 경우 TEOS 양의 변화에 따라서 상전이가 관찰되었으며, 1.2M TEOS에서 B2S:Eu2+ 단일상을 얻었을 수 있었다. 반면에 하소 과정을 거친 1.2M TEOS로 합성된 분말에서는 졸-겔법과 하이브리드법 모두 B2S:Eu2+와 미량의 BaSiO3:Eu2+ (BS:Eu2+) 상이 혼재하는 분말을 얻을 수 있었으나, 이들 분말은 하소 과정 없이 합성된 것보다 발광특성이 약 두배 정도 우수하였다. 하이브리드법에 의한 B2S:Eu2+는 졸-겔법에 의한 것에 비하여 발광강도가 약간 떨어지나 공정 시간을 획기적으로 단축 시킬 수 있는 장점을 보이고 있었다. 1.1M TEOS로 하소 과정을 거쳐 하이브리드법으로 얻어진 분말은 B2S:Eu2+ 단일상으로 구성되어 있었으며, Eu2+ 이온의 4f65d1 →4f7 전이에 의한 가장 강한 강도를 갖는 녹색 발광 (505 nm) 스펙트럼을 보이고 있었다.
Abstract
Ba2SiO4:Eu2+ (B2S:Eu2+) powders were prepared by firing the dry gel obtained by the sol-gel and the hybrid process (sol-gel and combustion), respectively, and their structure and luminescence were investigated. Tetraethyl orthosilicate (TEOS) was used as a Si source. The phase transition was observed with the TEOS content. With 1.2M TEOS, the powders prepared by the sol-gel process without prior calcination were composed of the B2S:Eu2+ single phase, whereas those by the sol-gel and the hybrid process with prior calcination consisted of the dominant B2S:Eu2+ and minor BaSiO3:Eu2+ (BS:Eu2+) phases and their emission intensities were approximately two times higher than those without prior calcination. The hybrid process could reduce the process time innovatively compared to the sol-gel process, even though the former was a little inferior to the latter in the emission intensity of B2S:Eu2+. With 1.1M TEOS, the B2S:Eu2+ single phase was obtained by the hybrid process, and its green emission was observed at 505 nm originated from the 4f65d1 →4f7 transition of Eu2+ ions.
참고문헌 (17)
- C. C. Lin, "Advances in phosphors for light-emitting diodes", J. Phys. Chem. Lett., 2, pp.1268~ (2011)
- J. K. Han, "Europium-activated barium", strontium silicates for near- UV light emitting diode applications, 2013, pp.133, 184~
- A. Birkel, "Eu2+-doped M2SiO4 (M = Ca, Ba) phosphors prepared by a rapid microwaveassisted sol-gel method: Phase formation and optical properties", Solid State Sci, 19, pp.51~ (2013)
- M. Zhang, "Optical properties of Ba2SiO4:Eu2+ phosphor for green light-emitting diode (LED)", Mater. Res. Bull., 42, pp.33~ (2007)
- J. S. Kim, "Temperature-dependent emission spectra of M2SiO4:Eu2+ (M = Ca, Sr, Ba) phosphors for green and greenish white LEDs", Solid State Commun, 133, pp.445~ (2005)
- J. S. Lee, "Effects of barium on luminescent properties of Sr2-xBaxSiO4:Eu2+ nanoparticles’", Ceram., Int., 39, pp.S555~ (2013)
- M. A. Lim, "Luminescence characteristics of green light emitting Ba2SiO4:Eu2+ phosphor", J. Mater. Sci. Lett., 22, pp.1351~ (2003)
- J. S. Kim, "Emission color variation of M2SiO4:Eu2+ (M = Ba, Sr, Ca) phosphors for light-emitting diode", Solid State Commun, 133, pp.187~ (2005)
- M. Wang, "Enhanced phosphorescence in N contained Ba2SiO4:Eu2+ for X-ray and cathode ray tubes", Opt. Mater, 32, pp.1042~ (2010)
- S. H. M. Poort, "Optical properties of Eu2+-activated orthosilicates and orthophosphates", J. Alloy. Compd, 260, pp.93~ (1997)
- M. Yamaga, "Radiative and nonradiative decay processes responsible for long-lasting phosphorescence of Eu2+-doped barium silicates", Phys. Rev. B, 71, pp.205102~ (2005)
- J. K. Park, "Luminescence characteristics of yellow emitting Ba3SiO5:Eu2+ phosphor", J. Mater. Sci, 40, pp.2069~ (2005)
- S. H. M. Poort, "Luminescence of Eu2+ in silicate host lattices with alkaline earth ions in a row", J. Alloy. Compd, 241, pp.75~ (1996)
- O. B. Tagiev, "Photoluminescence of a BaSiO3:Yb3+ crystal", J. Appl. Spectosc, 71, pp.541~ (2006)
- E. Tillmanns, "Refinement of tribarium silicate", Acta Cryst, 649, pp.B34~ (1978)
- I. S. Cho, "Investigation of crystal", electronic structure effects on the photoluminescence properties in the BaO-SiO2:Eu2+ systems, 2012, pp.132, 375~
- C. Guo, "Blue-White-Yellow tunable emission from Ce3+ and Eu2+ co-doped BaSiO3 phosphors", J. Electrochem. Soc., 158, pp.J373~ (2011)