Hostname: page-component-77c89778f8-sh8wx Total loading time: 0 Render date: 2024-07-18T14:52:56.901Z Has data issue: false hasContentIssue false
  • English
  • Français

Cerium Doped Garnet Phosphors for Application in White GaN-based LEDs

Published online by Cambridge University Press:  21 March 2011

Jennifer L. Wu ,
Steven P. Denbaars ,
Vojislav Srdanov  and
Henry Weinberg
Jennifer L. Wu
Affiliation:
Department of Chemical Engineering, University of California, Santa Barbara Santa Barbara, CA, 93106
Steven P. Denbaars
Affiliation:
Department of Materials, University of California, Santa Barbara Santa Barbara, CA, 93106
Vojislav Srdanov
Affiliation:
Center for Polymers and Organic Solids, University of California, Santa Barbara Santa Barbara, CA, 93106
Henry Weinberg
Affiliation:
Symyx Technologies, 3100 Central Expressway Santa Clara, CA, 95051
Get access

Abstract

Recently, renewed interest has emerged for the development of visible light, down-converting phosphors for application in white light emitting diodes (LEDs). In such devices, a blue GaN LED can act as a primary light source, serving as an efficient pump to excite photoluminescence in a phosphor with subsequent emission occurring at lower energies. The combination of blue light from the LED chip and emission from the phosphor(s) produces white light. It was recently reported that a combinatorial approach to synthesize and screen potential inorganic phosphors for use in white LEDs could aid in identifying improved phosphors for blue to yellow down conversion. Solid state thin-film arrays (libraries) based on the garnet structure (A1−x,Bx)3−z(C1−y,Dy)5O12:Ce3+z, where A, B = Y, Gd, Lu, La; C., D = Al, Ga; x and y = 0 to 1.0; and z = 0.03, were synthesized, and x-ray diffraction was used to select library samples of the crystalline garnet phase. Libraries of these various garnets were then characterized spectroscopically and their properties compared to traditionally prepared bulk powder phosphors of similar composition. Emission and excitation trends show that as larger cations are substituted for Y (A = Y), emission and excitation are red-shifted and as larger cations are substituted for Al (C = Al), emission and excitation are blue-shifted. If smaller cations are substituted for Y and Al an opposite trend is observed. Temperature dependence photoluminescence measurements and emission/excitation trends are also examined.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 667: Symposium G – Luminescence and Luminescent Materials , 2001 , G5.1
Copyright
Copyright © Materials Research Society 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Hide, F., Kozodoy, P., Denbaars, S.P., Heeger, A.J., Appl. Phys. Letters, 70(20), 2664–2666 (1997).Google Scholar
2. Schlotter, P., Schmidt, R., Schneider, J., Appl. Phys. A, 64, 417–418 (1997).Google Scholar
3. Baur, J., Schlotter, P., Schneider, J., Festkoerprobleme, 37, 67–78 (1998).Google Scholar
4. Nakamura, S., in Light-Emitting Diodes: Research, Manufacturing, and Applications, (Proceedings of SPIE, Feb 13-14, 1997), p. 26.Google Scholar
5. Nakamura, S., Fasol, G., The Blue Laser Diode, (Springer, Berlin, 1997), pp. 216–219.Google Scholar
6. Holloway, W. W. Jr, Kestigan, M., J. Opt. Soc. Am., 59 (1), 60–63 (1969).Google Scholar
7. Tien, T. Y., Gibbons, E.F., DeLosh, R.G., Zacmanidis, P.J., Smith, D.E., Stadler, H. L., J. Electrochem. Soc., 120 (2), 278–281 (1973).Google Scholar
8.U.S. Patent 6,013,199.Google Scholar
9. Ropp, R.C., The Chemistry of Artificial Lighting Devices, (Elsevier Science, New York, 1993), pp.502–504.Google Scholar
10. Wu, J. L., Devenney, M., Danielson, E., Poojary, D., Weinberg, H., Mater. Res. Soc. Symp. Proc., 560 (Luminescent Materials), 65–70 (1999).Google Scholar
11. Wu, J. L., Denbaars, S. P., Massick, S., Srdanov, V., Weinberg, H., in preparation.Google Scholar