Al2O3:xCr2O3 고용상의 발광특성과 적색형광체의 연색성 향상을 위한 첨가제로의 응용 |
채기웅, 천채일, 김정석1 |
호서대학교 신소재공학과 1호서대학교 BK21 대학원 반도체디스플레이공학과 |
Photoluminescence of Al2O3:xCr2O3 Solid Solution and Application as the Additive for Improving CRI of Red Phosphor |
Ki-Woong Chae, Chae-Il Cheon, Jeong-Seog Kim1 |
Department of Materials Science and Engineering, Hoseo University 1Department of BK21 Semiconductor & Display Engineering, Hoseo University |
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ABSTRACT |
In this article photoluminescence of the $Al_2O_3:xCr_2O_3$ solid solutions prepared by solid state reaction method are represented. The effect of $Cr_2O_3$-activator concentration and heat treatment time on the PL characteristics have been discussed in conjunction with microstructure of phosphor samples. The $Al_2O_3:xCr_2O_3$ phosphors show the highest PL intensity at x=0.003 mole when the samples are reacted at $1600^{circ}C$ for 5 h. The PL emission and absorption spectra show the maximum peaks at 698 nm and at 398 nm respectively. The CIE color coordinate is (x=0.646, y=0.316) at 0.003 mole $Cr_2O_3$, which value is very close to the NTSC coordinate of red color. This characteristic feature of $Al_2O_3:xCr_2O_3$ has been applied for an additive to improve the color characteristic of other red phosphor $LiEuW_2O_8$ which has a relatively poor color purity with an emission peak centered at 615 nm and with a CIE coordinate (x=0.530, y=0.280). The $Al_2O_3:0.003Cr_2O_3$ phosphor has been mixed with the $LiEuW_2O_8$ phosphor powder and the PL characteristics and CIE color coordinates are characterized. The $Al_2O_3:xCr_2O_3$ phosphor was found effective for improving the CRI (color rendering index) of $LiEuW_2O_8$ phosphor. |
Key words:
Phosphor, Alumina, Cr-activator, Color coordinate, $LiEuW_2O_8$ |
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