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Photoluminescence Excitation Study of Lo-Phonon Assisted Excitonic Transitions in Gan

Published online by Cambridge University Press:  10 February 2011

S. J. Hwang ,
Y. H. Cho ,
J. J. Song ,
W. Shan  and
Y. C. Chang
S. J. Hwang
Affiliation:
Center for Laser and Photonics Research and Department of Physics, Oklahoma State University, Stillwater, OK 74078
Y. H. Cho
Affiliation:
Center for Laser and Photonics Research and Department of Physics, Oklahoma State University, Stillwater, OK 74078
J. J. Song
Affiliation:
Center for Laser and Photonics Research and Department of Physics, Oklahoma State University, Stillwater, OK 74078
W. Shan
Affiliation:
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
Y. C. Chang
Affiliation:
Department of Physics and Materials Research Laboratory, University of Illinois, Urbana-Champaign, IL 61801
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Abstract

We report the results of a photoluminescence excitation (PLE) study on excitonic transitions in GaN. PLE measurements were carried out as a function of temperature to investigate exciton formation, thermalization, and annihilation processes in GaN. The PLE spectra detected at free-exciton resonance were found to exhibit a large number of oscillatory emission structures with an energy spacing of LO-phonon (92 meV), and such emission persisted up to 400K. The observation suggests that a phonon-assisted indirect exciton formation process, which simultaneously generates a free-exciton and an LO-phonon, is very significant and efficient in GaN, and the lifetime of the free-exciton is longer than the relaxation time of LO-phonon emission but much shorter than that of acoustic-phonon emission. The appearance of the broad spectral features at the PLE spectrum detected at free-exciton resonance, similar to those measured at the boundexciton resonance, is attributed to the higher order transition processes which involve acousticphonon scattering and thermal repopulation of free-excitons. In addition, we observed up to the 12th LO-phonon emission in PLE spectrum around 120 K, indicating the existence of the excitons with a large kinetic energy in GaN.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 482 , 1997 , 691
Copyright
Copyright © Materials Research Society 1998

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References

1. See for example, MRS Bulletin 22 (1997).Google Scholar
2. Morkoq, H., Strite, S., Gao, G.B., Lin, M.E., Sverdlov, B., and Bums, M., J. Appl. Phys. 76, 1363 (1994).Google Scholar
3. Nakamura, S. and Fasol, G., The Blue Laser Diode, (Springer, New York, 1997).Google Scholar
4. Nakamura, S., Senoh, M., Nagahama, S., Iwasa, N., Yamada, T., Matsushita, T., Kiyoku, H., and Sugimoto, Y., Jpn. J. Appl. Phys. 35, part.2, L74 (1996); Appl. Phys. Lett. 68, 2105 (1996).Google Scholar
5. Akasaki, I., Sota, S., Sakai, H., Tanaka, T., Koike, M., and Amano, H., Eletron. Lett. 32, 1105 (1996).Google Scholar
6. Mack, M.P., Abare, A., Aizcorbe, M., Kozodoy, P., Keller, S., Mishra, U. K., Coldren, L., and DenBaars, S., MRS Internet J. Nitride Semicond. Res. 2, 41 (1997).Google Scholar
7. Planel, R., Bonnot, A., Benoit d la Guillaume, C., Phys. Stat. Sol.(b), 58, 251 (1973).Google Scholar
8. Ueta, M., Kanzaki, H., Kobayashi, K., Toyozawa, Y., and Hanamura, E., Excitonic Processes in Solids, (Springer, New York, 1986).Google Scholar
9. Permogorov, S., Phys. Stat. Sol. 68, 9 (1975).Google Scholar
10. Kovalev, D., Averboukh, B., Volm, D., Meyer, B.K., Amano, H., and Akasaki, I., Phys. Rev. B54, 2518(1996); Mat. Res. Soc. Symp. Proc. Vol.449, 701 (1997).Google Scholar