CuCl 농도에 따른 SrS:CuCl 박막 전계발광소자의 발광특성

Luminescent Characteristics of SrS:CuCl Thin-Film Electroluminescent(TFEL) Devices on CuCl Concentrations

  • 이순석 (충북대학교 전기전자컴퓨터공학부) ;
  • 임성규 (단국대학교 전자컴퓨터공학부)
  • 발행 : 2002.08.01

초록

전자빔 증착 장비를 이용하여 SrS:CuCl TFEL 소자를 제작한 후, 발광특성을 조사하였다. 형광체 모체는 SrS 분말을 사용하였고, 발광중심체로는 CuCl 분말을 0.05 ~ 0.6 at% 범위에서 첨가하였다. 증착 온도 500℃, 전자빔 전류 20 ~ 40 mA 및 증착율 5 ~ 10 /sec의 조건에서 형광층 두께를 6000 으로 증착시켰다. CuCl 농도가 낮을 때에는 monomer, dimer, trimer 및 tetramer 발광센터에 의한 청색 발광을 확인할 수 있었으나 휘도가 낮았다. CuCl 농도가 높을 때에는 dimer와 trimer 발광센터에 의한 밝은 녹청색 빛을 방출하였다. 최적의 발광특성은 CuCl 농도를 0.2 at% 첨가한 SrS:CuCl TFEL 소자에서 관찰되었으며, 문턱전압, 휘도(L/sub 40/), 효율(η/sub 20/) 및 CIE 색좌표는 각각 55 V, 728 cd/㎡, 0.49 lm/W 및 (0.21, 0.33)을 나타내었다.

The SrS:CuCl TFEL devices were fabricated by electron-beam deposition and the luminescent characteristics of the fabricated SrS:CuCl TFEL devices were studied. The SrS powder was used as the host materials and 0.05 ~ 0.6 at% of CuCl powder was added as the luminescent center. The deposition conditions of substrate temperature, electron beam current, and deposition rate were 500 $^{\circ}C$ , 20 ~ 40 mA, and 5 ~ 10 /sec, respectively The total thickness of the phosphor layer deposited was 6000 . The blue emission at low CuCl concentrations was observed from the luminescent centers of monomer, dimer, trimer, and tetramer, The bright greenish blue emission at high CuCl concentrations was observed from the dimer and trimer luminescent centers. The maxium luminance was observed from the SrS:CuCl TFEL devices doped with 0.2 at% of CuCl concentration and the threshold voltage, luminance(L$_{40}$ ), efficiency(η$_{20}$) and CIE coordinate obtained were 55 V, 728 cd/$m^2$, 0.49 lm/w, and (0.21, 0.33), respectively..

키워드

참고문헌

  1. W. A. Barrow, R. W. Coovert, and C. N. King, 'Strontium sulphide : the host for a new high-efficiency thin-film EL blue phosphor,' SID 84 digest, pp. 249-250, 1984, USA
  2. W. A. Barrow, R. E. Coovert, E. Dickey, C. N. King, C. Laakso, S. S. Sun, R. T. Tuenge, R. C. Wentross, and J. Kane, 'A new class of blue TFEL phosphors with application to a VGA full-color display,' SID 93 digest, pp. 761-764, 1993, USA
  3. S. S. Sun and Eric Dickey, 'A bright and efficient new blue TFEL phosphor,' 17th IDRC, pp. 301-304, sep., 1997, Toronoto,Canada
  4. W. Park, T. C. Jones, W. Tong, B. K. Wagner, C. J. Summers, and S. S. Sun, 'Luminescence properties of a new bright electroluminescent phosphor SrS:Cu,' The third international conference of the science and technology of display phosphors, pp. 57-59, nov., 1997, California, USA
  5. 이순석, 임성규, '고휘도 청색 발광 SrS:CuCl 박막 전계발광소자의 제작,' 전자공학회 논문지 제 37권 SD편, 제 1 호, pp. 36-43, 2000 년 1 월
  6. Joint commission for powder diffraction standards(JCPDS) card, 8-489
  7. N. Yamashita, K. Ebisumori, and K. Nalamura, 'Photoluminescence properties of the (Ca,Sr) $S:Cu^+$ powder phosphors,' J. Lumin., Vol. 62, pp. 25-31, 1994 https://doi.org/10.1016/0022-2313(94)90072-8
  8. H. Kasano, K. Megume, and H. Yamamoto, 'Cathodolunimescence of Cal-xMgxS:A(A = Cu or Ce),' J. Electorchem. Soc., Vol. 131, pp. 1953-1960, 1984 https://doi.org/10.1149/1.2115999
  9. Y. Nakanishi, K. Natsume, Y. Fukuda, G. Shimaoka, 'Luminescent properties of CaS phosphors activated by copper and fluorine,' J. Crystal Growth, Vol. 101, pp. 462-465, 1990 https://doi.org/10.1016/0022-0248(90)91015-I
  10. N. Yamashita, K. Ebismori, and K. Nakamura, 'Luminescence from the aggeregated Cu centers in $SrS:Cu^+$,' J. Appl. Phys., Vol. 32, pp. 3845-3850, 1993
  11. S. S. Sun, 'Blue emitting SrS:Ag,Cu TFEL devices,' The forth international conference on the science and technology of display phosphors, pp. 183-186, sep., 1998, Oregon, USA
  12. U. Troppenz, B. Hiitl, U. Storz, P. Kratzert, and K. O. Velthaus, 'Photoluminescence and electroluminescence studies on Cu and Ag doped Srs ACTFEL devices,' The fourth international conference on the science and technology of display phosphors, pp. 187-190, sep., 1998, Oregon, USA