Hostname: page-component-745bb68f8f-cphqk Total loading time: 0 Render date: 2025-02-05T21:25:40.114Z Has data issue: false hasContentIssue false
  • English
  • Français

Localized Excitons in InGaN

Published online by Cambridge University Press:  10 February 2011

S. ChichiBu ,
T. Deguchi ,
T. Sota ,
K. Wada  and
S. Nakamura
S. ChichiBu
Affiliation:
Materials Department, University of California, Santa Barbara, CA 93106, and also Faculty of Science and Technology, Science University of Tokyo, 2641 Yamazaki, Noda, Chiba 278, Japan
T. Deguchi
Affiliation:
Department of Electrical, Electronics, and Computer Engineering, Waseda University, 3–4–1– Ohkubo, Shinjuku, Tokyo 169, Japan
T. Sota
Affiliation:
Department of Electrical, Electronics, and Computer Engineering, Waseda University, 3–4–1– Ohkubo, Shinjuku, Tokyo 169, Japan
K. Wada
Affiliation:
Compound Semiconductor Materials Research, NTT” System Electronics Laboratories, 3–1 Morinosato-Wakamiya, Atsugi, Kanagawa 243–01, Japan
S. Nakamura
Affiliation:
Department of Research and Development, Nichia Chemical Industries Ltd., 491 Oka, Kaminaka, Anan, Tokushima 774, Japan
Get access

Abstract

Emission mechanisms of the device-quality quantum well (QW) structure and bulk three dimensional (3D) InGaN materials grown on sapphire substrates without any epitaxial lateral overgrown GaN (ELOG) base layers were investigated. The InxGx1−xN layers showed various degree of spatial potential (bandgap) fluctuation, which is probably due to a compositional inhomogeneity or monolayer thickness fluctuation produced by some kinetic driving forces initiated by the threading dislocations (TDs) or growth steps during the growth. The degree of fluctuation changed remarkably around nominal InN molar fraction x=0.2, which changes to nearly 8–10 % for the strained InxGa1−xN. This potential fluctuation induces energy tail states both in QW and 3D InGaN, showing a large Stokes-like shift combined with the red shift due to quantum confined Stark effect (QCSE) induced by the piezoelectric field. The spontaneous emission from undoped InGaN single quantum well (SQW) light-emitting diodes (LED's), undoped 3D double heterostructure (DH) LED's, and multiple quantum well (MQW) laser diode (LD) wafers was assigned as being due to the recombination of excitons localized at the potential minima, whose area was determined by cathodoluminescence (CL) mapping to vary from less than 60 nm to 300 nm in lateral size in the case of QW's. The lasing mechanisms of the cw In0.15Gao.85N MQW LD's having small potential fluctuation, whose bandgap broadenings are less than about 50 meV, can be described by the well-known electron-hole-plasma (EIHP) picture with Coulomb enhancement. The inhomogenous MQW LD's are considered to lase by EHP in segmented QW's or Q-disks. It is desirable to use entire QW planes with small potential inhomogeneity as gain media for higher performance LD operation.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 482 , 1997 , 613
Copyright
Copyright © Materials Research Society 1998

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

1. Important data and references are cited in the textbook [Nakamura, S. and Fasol, G., The Blue Laser Diode, (Springer, Berlin, 1997)]; recent data are from S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, Y Sugimoto, H. Kiyoku, Jpn J. Appl. Phys. 36, L 1059 (1997); They further adopted a modulation-doped superlattice cladding layers and ELOG layers, and the accelaration test has been done at 50°0C [S. Nakamura, presented at The 2nd Intemati. Conf. on Nitride Semiconductors, Tokushima, Japan, Oct. 27–31, 1997].Google Scholar
2. Akasaki, I., Sota, S., Sakai, H., Tanaka, T., Koike, M. and Amano, H., Electron. Lett. 32,1105 (1996).Google Scholar
3. Itaya, K., Onomura, M., Nishio, J., Sugiura, L., Saito, S., Suzuki, M., Rennie, J., Nunoue, S., Yamamoto, M., Fujimoto, H., Kokubun, Y., Ohba, Y, Hatakoshi, G., and Ishikawa, M., Jpn. J. Appl. Lett. 35, L1315 (1996).Google Scholar
4. Bulman, G. E., Doverspike, K., Sheppard, S. T., Weeks, T. W., Kong, H. S., Dieringer, H. M., Edmond, J. A., Brown, J. D., Swindell, J.T., and Schetzina, J. F., Electron. Lett. 33, 1556 (1997).Google Scholar
5. Kuramata, A., Domen, K., Soejima, R., Horino, K., Kubota, S., and Tanahashi, T., Proc. 2nd Intemati. Conf. on Nitride Semiconductors, (Tokushima, Japan, 1997) pp450.Google Scholar
6. Mack, M. P., Abare, A., Aizcorbe, M., Kozodoy, P., Keller, S., Mishra, U. K., Coldren, L. A., and DenBaars, S. P., Mater. Res. Soc. Internet J. Nitride Semicond. Res. 2, 41 (1997).Google Scholar
7. Koukitsu, A., Takahashi, N., Taki, T., and Seki, H., Jpn. J. Appl. Phys. 35, L673 (1996).Google Scholar
8. Ho, I-hsiu and Stringfellow, G. B., Appl. Phys. Lett. 69, 2701 (1996).Google Scholar
9. Matsuoka, T., Appl. Phys. Lett. 71, 105 (1997).Google Scholar
10. Takeuchi, T., Takeuchi, H., Sota, S., Sakai, H., Amano, H., and Akasaki, I., Jpn. J. Appl. Phys. 36, L177 (1997); Proc. 2nd Intemati. Conf. on Nitride Semiconductors, (Tokushima, Japan, 1997) pp.450.Google Scholar
11. Chichibu, S., Azuhata, T., Sota, T. and Nakamura, S., J. Appl. Phys. 79,2784 (1996); Proc. Int. Symp. On Blue Laser and Light Emitting Diodes (Ohmsha, Tokyo, 1996), -pp.202; S. Chichibu, H. Okumura, S. Nakamura, G. Feuillet, T. Azuhata, T. Sota and S. Yoshida, Jpn. J. Appl. Phys. 36, 1976 (1997).Google Scholar
12. Monemar, B., Bergman, J. P., Amano, H., Akasaki, I., Detchprohm, T., Hiramatsu, K., and Sawaki, N., Proc. Int Symp. on Blue Laser and Light Emitting Diodes (Ohmsha, Tokyo, 1996), pp. 135.Google Scholar
13. Chichibu, S., Azuhata, T., Sota, T., and Nakamura, S., 38th Electron. Mater. Conf., Santa Barbara, CA, June 26–28, 1996, Late News Paper W-10; Appl. Phys. Lett. 69,4188 (1996); Mater. Res. Soc. Symp. Proc. Vol.449, 653 (1997); Appl. Phys. Lett. 70, 2822 (1997).Google Scholar
14. Narukawa, Y., Kawakami, Y, Fujita, Sz., Fujita, Sg., and Nakamura, S., Phys. Rev. B 55, R1938 (1997); Y Narukawa, Y Kawakami, M. Funato, Sz. Fujita, Sg. Fujita, and S. Nakamura, Appl. Phys. Lett. 70,981 (1997).Google Scholar
15. Chichibu, S., Wada, K., and Nakamura, S., Appl. Phys. Lett. 71,2346 (1997).Google Scholar
16. Smith, M., Chen, G., Lin, J. Y., Jiang, H., Khan, M. A., and Chen, Q., Appl. Phys. Lett. 69,2837 (1996).Google Scholar
17. Scholz, F., Haerle, V., Steuber, F., Sohmer, A., Bolay, H., Syganow, V., Doemen, A., Im, J. A-S., Hangleiter, A., Duboz, J. Y., Galtier, P., Rosencher, E., Ambacher, O., Brunner, D., and Lakner, H., Mater. Res. Soc. Symp. Proc. Vol.,449, 3 (1997).Google Scholar
18. Sugawara, M., Phys. Rev. B 51, 10743 (1995).Google Scholar
19. For a review, see for example, Haug, H. and Koch, S. W., Quantum Theory of the Optical and Electronic Propres of Semiconductors, (World Scientific, Singapore, 1990) and W. W. Chow, S. W. Koch, and M. Sargent II, Semiconductor-Laser Physics, (Springer, Berlin, 1994); W. W. Chow, A. F Wright and J. S. Nelson, Appl. Phys. Let. 68, 296 (1996).Google Scholar
20. Cardona, M., in Modulation Spectroscopy, Solid State Physics Suppl. 11, ed. Seitz, S., Tumbull, D. and Ehrenreich, H. (Academic, New York, 1969); D. E. Aspnes, Handbook on Semiconductors, ed. T. S. Moss (North-Holland, Amsterdam, 1980) Vol. 2, Chap. 4A, p. 109; D. E. Aspnes, Surf. Sci. 37, 418 (1973).Google Scholar
21. Shaldee, K. L. and Leheny, R. F., Appl. Phys. Left. 18,475 (1971); K. L. Shaklee, R. F. Leheny, and R. E. Nahory, Appl. Phys. Lett. 19, 302 (1971).Google Scholar
22. Deguchi, T., Azuhata, T., Sota, T., Chichibu, S., and Nakamura, S., European Mater. Res. Soc. 1997 Spring Meeting, Strasbourg, France, Jun.16–20, 1997, L-XIII-3; to be published in Mater. Sci. Engineering B.Google Scholar
23. Azuhata, T., Sota, T., Suzuki, K., and Nakamura, S., J. Phys. Condens. Mat. 7, L129 (1995); T. Azuhata, T. Matsunaga, K. Shimada, K. Yoshida, T. Sota, K. Suzuki, and S. Nakamura Physica B 219/220, 493 (1996).Google Scholar
24. Chichibu, S., Mizutani, T., Shioda, T., Nakanishi, H., Deguchi, T., Azuhata, T., Sota, T, and Nakamura, S., Appl. Phys. Lett. 70,3440 (1997).Google Scholar
25. Chichibu, S., Shikanai, A., Azuhata, T., Sota, T., Kuramata, A., Horino, K., and Nakamura, S., Appl. Phys. Lett. 68,3766 (1996); A. Shikanai, T Azuhata, T. Sota, S. Chichibu, A. Kuramata, K. Horino, and S. Nakamura, J. Appl. Phys. 81, 417 (1997).Google Scholar
26. Suzuki, M., Uenoyama, T., and Yanase, A., Phys. Rev. B 52, 8132 (1995).Google Scholar
27. Dingle, R-, Sell, D. D., Stokowski, S. E., and Ilegems, M., Phys. Rev. B 4, 1211 (1971).Google Scholar
28. Monemar, B., Phys. Rev. B 10, 676 (1974).Google Scholar
29. Shirakata, S. and Chichibu, S., J. Appl. Phys. 80, 2043 (1996).Google Scholar
30. Im, J. S., Haerle, V., Scholz, F., and Hangleiter, A., MRS Internet J. Nitride Semicond. Res. 1, 37 (1996).Google Scholar
31. Smith, D. L. and Mailhiot, C., Phys. Rev. Lett. 58, 1264 (1987).Google Scholar
32. The piezoelectric field was calculated with the values ofpiezoelectric constants of GaN according to Halsall, M. P., Nicholls, J. E., Davies, J. J., Cockayne, B., and Wright, P. J. [J. Appl. Phys. 71, 907 (1992)], and the Stark shift due to the electric field was calculated by the variational method neglecting exciton binding energy. Calculations are based on work by D. A. Miller, D. S. Chemla, T. C. Damen, A. C. Gross, W. Wiegmann, T. H. Wood, and C. A. Burrus [Phys. Rev. Lett 53,2173(1981) and Phys. Rev. B 32, 1043 (1985)].Google Scholar
33. Harris, C. I., Monemar, B., Amano, H., and Akasaki, I., Appl. Phys. Lett. 67,840 (1995).Google Scholar
34. Taguchi, T., Maeda, T., Yamada, Y, Nakamura, S., and Shinomiya, G., Proc. Int. Symp. On Blue Laser and Light Emitting Diodes (Ohmsha, Tokyo, 1996), p.372.Google Scholar
35. Keller, S., Keller, B. P., Minsky, M. S., Bowers, J. E., Mishra, U. K., DenBaars, S. P., and Seifert, W, presented at The 2nd International Conf. on Nitride Semiconductors, Tokushima, Japan, Oct.27–31, 1997, Session M2–5; and also a private communication.Google Scholar
36. Uenoyama, T., Phys. Rev. B 51, 10228 (1995); and also a private communication.Google Scholar
37. Sato, H., Sugahara, T., Naoi, Y, and Sakai, S., Proc. 2nd Intemati. Conf. on Nitride Semiconductors, (Tokushima, Japan, 1997) p. 28.Google Scholar
38. Kisielowski, C. and Liliental-Weber, Z. (private communication); they have observed a dot-like nanoscale compositional disorder in the SQW LED wafers using the electron scattering potential mapping method.Google Scholar
39. Ponce, F. A., presented at European Mater. Res. Soc. 1997 Spring Meeting, Strasbourg, France, Jun. 16–20, 1997, No. L-VII.4 (late news).Google Scholar
40. H. -Kwon, J., Lee, Y. H., Miki, O., Yamano, H., and Yoshida, A., Appl. Phys. Lett. 69,937 (1996).Google Scholar
41. Sota, T., Chichibu, S., and Nakamura, S. (private communication). The Eex. value in GaN/Al0.1Ga0.9N QW was calculated by the variational method according to G. Bastard, E. E. Mendez, L. L.Chang, and L. Esaki [Phys. Rev. B 26, 1974 (1982)]. In the calculation, we started from the Hamiltonian suitable to QW's including mass and dielectric constant anisotropy, assuming an infinite barrier height to simplify the calculation. After variable transformations for Z coordinates (perpendicular to the QW plane) which formally remove the mass anisotropy in the Harniltonian, Eex was calculated using the trial function for the excitonic relative motion given by exp{-[p 2+(Ze−Zn)2]1/2/λ}, considering the fact that the 3D exciton Bohr radius is as small as 3.4 nm. Here λ is the variational parameter, p is the absolute value of the relative position of electron and hole in the QW plane, and Ze(Zn) is the transformed Z coordinate of the electron (hole).Google Scholar
42. Frankowsky, G., Steuber, F., Haerle, V, Scholz, F, and Hangleiter, A., Appl. Phys. Lett. 68, 3746 (1996).Google Scholar
43. Kuball, M., Jeon, E. -S., Song, Y -K., Nurmikko, A., Kozodoy, P., Abare, A., Keller, S., Coldren, L. A., Mishra, U. K., DenBaars, S. P., and Steigerwald, D. A., Appl. Phys. Leat. 70,2580 (1997).Google Scholar
44. Chen, W., Fritze, M., Nurmikko, A. V., Ackley, D., Covard, C., and Lee, H., Phys. Rev. Lett. 64, 2434 (1990).Google Scholar
45. Mueller, J. F., Phys. Rev. B 42, 11189 (1990).Google Scholar