Abstract

The indices of refraction, extinction constants and complex conductivities of the GaN film for frequencies ranging from 0.2 to 2.5 THz are obtained using THz time-domain spectroscopy. The results correspond well with the Kohlrausch stretched exponential model. Using the Kohlrausch model fit not only provides the mobility of the free carriers in the GaN film, but also estimates the relaxation time distribution function and average relaxation time.

© 2006 Optical Society of America

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    [CrossRef]
  2. S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, Y. Sugimoto, and H. Kiyoku, "Room-temperature continuous-wave operation of InGaN multi-quantum-well structure laser diodes with a lifetime of 27 hours," Appl. Phys. Lett. 70, 1417-1419 (1997).
    [CrossRef]
  3. S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, H. Kiyoku, and Y. Sugimoto, "InGaN-based multi-quantum-well-structure laser diodes," Jpn. J. Appl. Phys.,  35, L74-L76 (1996).
    [CrossRef]
  4. F. A. Ponce, and D. P. Bour, "NItride-based semiconductors for blue and green light-emitting devices," Nature 386, 351-359, (1997).
    [CrossRef]
  5. X. A. Cao, J. M. Teetsov, M. P. D'Evelyn, D. W. Merfeld, and C. H. Yan, "Electrical characteristics of InGaN/GaN light-emitting diodes grown on GaN and sapphire substrates," Appl. Phys. Lett. 85, 7-9 (2004).
    [CrossRef]
  6. D. I. Florescu, J. C. Ramer, D. S. Lee, and E. A. Armour, "InGaN/GaN single-quantum-well light-emitting diodes optical output efficiency dependence on the properties of the barrier layer separating the active and p-layer regions," Appl. Phys. Lett. 84, 5252-5254 (2004).
    [CrossRef]
  7. K. S. Ramaiah, Y. K. Su, S. J. Chang, B. Kerr, H. P. Liu, and I. G. Chen, "Characterization of InGaN/GaN multi-quantum-well blue-light-emitting diodes grown by metal organic chemical vapor deposition," Appl. Phys. Lett. 84, 3307-3309 (2004).
    [CrossRef]
  8. D. C. Reynolds, D. C. Look, B. Jogai, A. W. Saxler, S. S. Park, and J. Y. Hahn, "A giant magnetoresistance sensor for high magnetic field measurements," Appl. Phys. Lett. 77, 1879-1881 (2000).
    [CrossRef]
  9. D. C. Reynolds, B. Jogai, and T. C. Collins, "Longitudinal Excitons in GaN," Appl. Phys. Lett. 80, 3928-3930 (2002).
    [CrossRef]
  10. A. Kasic, M. Schubert, S. Einfeldt, D. Hommel, and T. E. Tiwald, "Free-carrier and phonon properties of n- and p-type hexagonal GaN films measured by infrared ellipsometry," Phys. Rev. B 62, 7365-7377 (2000).
    [CrossRef]
  11. A. Yasan, R. McClintock, K. Mayes, S. R. Darvish, H. Zhang, P. Kung, M. Razeghi, S. K. Lee, and J. Y. Han, "Comparison of ultraviolet light-emitting diodes with peak emission at 340 nm grown on GaN substrate and sapphire," Appl. Phys. Lett. 81, 2151-2153 (2002).
    [CrossRef]
  12. W. J. Moore, J. A. Freitas, Jr., S. K. Lee, S. S. Park, and J. Y. Han, "Magneto-optical studies of free-standing hydride-vapor-phase epitaxial GaN," Phys. Rev. B 65, 081201 (2002).
    [CrossRef]
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    [CrossRef]
  14. K. T. Tsen, R. P. Joshi, D. K. Ferry, A. Botchkarev, B. Sverdlov, A. Salvador, and H. Morkoc, "Nonequilibrium electron distributions and phonon dynamics in wurtzite GaN," Appl. Phys. Lett. 68, 2990-2992 (1996).
    [CrossRef]
  15. T. P. Chow, and R. Tyagi, "Wide bandgap compound semiconductors for superior high-voltage unipolar power devices," IEEE Trans. Electron. Dev. 41, 1481-1483 (1994).
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    [CrossRef]
  17. S. J. Pearton, J. C. Zolper, R. J. Shul, and F. Ren, "GaN: Processing, defects, and devices," J. Appl. Phys. 86, 1-78 (1999).
    [CrossRef]
  18. H. Morkoc, S. Strite, G. B. Gao, M. E. Lin, B. Sverdlov, and M. Burns, "Large-band-gap SiC, III-V nitride, and II-VI ZnSe-based semiconductor device technologies," J. Appl. Phys. 76, 1363-1398 (1994).
    [CrossRef]
  19. W. Zhang, A. K. Azad, and D. Grischkowsky, "Terahertz studies of carrier dynamics and dielectric response of n-type, freestanding epitaxial GaN," Appl. Phys. Lett. 82, 2841-2843 (2003).
    [CrossRef]
  20. T. Nagashima, K. Takata, S. Nashima, H. Harima, and M. Hangyo, "measurement of electrical properties of GaN thin films using terahertz-time domain spectroscopy," Jpn. J. Appl. Phys.,  44, 926-931 (2005).
    [CrossRef]
  21. T. I. Jeon, and D. Grischkowsky, "Nature of conduction in doped silicon," Phys. Rev. Lett. 78, 1106-1109 (1997).
    [CrossRef]
  22. M. C. Beard, G. M. Turner, and C. A. Schmuttenmaer, "Transient photoconductivity in GaAs as measured by time-resolved terahertz spectroscopy," Phys. Rev. B 62, 15764-15777 (2000).
    [CrossRef]
  23. N. V. Smith, "Classical generalization of the Drude formula for the optical conductivity," Phys. Rev. B 64, 155106 (2001).
    [CrossRef]
  24. D. W. Davidson and R. H. Cole, "Dielectric Relaxation in Glycerol, Propylene Glycol, and n-Propanol," J. Chem. Phys. 19, 1484-1490 (1951).
    [CrossRef]
  25. P. Gilard and J. deBast, in Advances in Glass Technology (Plenum, New York, 1962), p. 442.
  26. G. Williams and D. C. Watts, "Non-Symmetrical Dielectric Relaxation Behaviour Arising from a Simple Empirical Decay Function," Trans. Faraday Soc. 66, 80-85 (1970).
    [CrossRef]
  27. A. S. Barker, Jr. and M. Ilegems, "Infrared Lattice Vibrations and Free-Electron Dispersion in GaN," Phys. Rev. B 7, 743-750 (1973).
    [CrossRef]
  28. C. P. Lindsey and G. D. Patterson, "Detailed comparison of the Williams-Watts and Cole-Davidson functions," J. Chem. Phys. 73, 3348-3357 (1980).
    [CrossRef]
  29. F. Alvarez, A. Alegria, and J. Colmenero, "Relationship between the time-domain Kohlrausch-Williams-Watts and frequency-domain Havriliak-Negami relaxation functions," Phys. Rev. B 44, 7306-7312 (1991).
    [CrossRef]
  30. M. Tyagi, A. Alegria, and J. Colmenero, "Heterogeneous dynamics of poly(vinyl acetate) far above Tg:A combined study by dielectric spectroscopy and quasielastic neutron scattering," J. Chem. Phys. 122, 2449091-24490913 (2005).
    [CrossRef]
  31. D. Grischkowsky, S. R. Keiding, M. van Exter, and Ch. Fattinger, "Far-infrared time-domain spectroscopy with terahertz beams of dielectrics and semiconductors," J. Opt. Soc. Am. B 7, 2006-2015 (1990).
    [CrossRef]

2005 (2)

T. Nagashima, K. Takata, S. Nashima, H. Harima, and M. Hangyo, "measurement of electrical properties of GaN thin films using terahertz-time domain spectroscopy," Jpn. J. Appl. Phys.,  44, 926-931 (2005).
[CrossRef]

M. Tyagi, A. Alegria, and J. Colmenero, "Heterogeneous dynamics of poly(vinyl acetate) far above Tg:A combined study by dielectric spectroscopy and quasielastic neutron scattering," J. Chem. Phys. 122, 2449091-24490913 (2005).
[CrossRef]

2004 (3)

X. A. Cao, J. M. Teetsov, M. P. D'Evelyn, D. W. Merfeld, and C. H. Yan, "Electrical characteristics of InGaN/GaN light-emitting diodes grown on GaN and sapphire substrates," Appl. Phys. Lett. 85, 7-9 (2004).
[CrossRef]

D. I. Florescu, J. C. Ramer, D. S. Lee, and E. A. Armour, "InGaN/GaN single-quantum-well light-emitting diodes optical output efficiency dependence on the properties of the barrier layer separating the active and p-layer regions," Appl. Phys. Lett. 84, 5252-5254 (2004).
[CrossRef]

K. S. Ramaiah, Y. K. Su, S. J. Chang, B. Kerr, H. P. Liu, and I. G. Chen, "Characterization of InGaN/GaN multi-quantum-well blue-light-emitting diodes grown by metal organic chemical vapor deposition," Appl. Phys. Lett. 84, 3307-3309 (2004).
[CrossRef]

2003 (1)

W. Zhang, A. K. Azad, and D. Grischkowsky, "Terahertz studies of carrier dynamics and dielectric response of n-type, freestanding epitaxial GaN," Appl. Phys. Lett. 82, 2841-2843 (2003).
[CrossRef]

2002 (3)

A. Yasan, R. McClintock, K. Mayes, S. R. Darvish, H. Zhang, P. Kung, M. Razeghi, S. K. Lee, and J. Y. Han, "Comparison of ultraviolet light-emitting diodes with peak emission at 340 nm grown on GaN substrate and sapphire," Appl. Phys. Lett. 81, 2151-2153 (2002).
[CrossRef]

W. J. Moore, J. A. Freitas, Jr., S. K. Lee, S. S. Park, and J. Y. Han, "Magneto-optical studies of free-standing hydride-vapor-phase epitaxial GaN," Phys. Rev. B 65, 081201 (2002).
[CrossRef]

D. C. Reynolds, B. Jogai, and T. C. Collins, "Longitudinal Excitons in GaN," Appl. Phys. Lett. 80, 3928-3930 (2002).
[CrossRef]

2001 (1)

N. V. Smith, "Classical generalization of the Drude formula for the optical conductivity," Phys. Rev. B 64, 155106 (2001).
[CrossRef]

2000 (3)

M. C. Beard, G. M. Turner, and C. A. Schmuttenmaer, "Transient photoconductivity in GaAs as measured by time-resolved terahertz spectroscopy," Phys. Rev. B 62, 15764-15777 (2000).
[CrossRef]

A. Kasic, M. Schubert, S. Einfeldt, D. Hommel, and T. E. Tiwald, "Free-carrier and phonon properties of n- and p-type hexagonal GaN films measured by infrared ellipsometry," Phys. Rev. B 62, 7365-7377 (2000).
[CrossRef]

D. C. Reynolds, D. C. Look, B. Jogai, A. W. Saxler, S. S. Park, and J. Y. Hahn, "A giant magnetoresistance sensor for high magnetic field measurements," Appl. Phys. Lett. 77, 1879-1881 (2000).
[CrossRef]

1999 (1)

S. J. Pearton, J. C. Zolper, R. J. Shul, and F. Ren, "GaN: Processing, defects, and devices," J. Appl. Phys. 86, 1-78 (1999).
[CrossRef]

1998 (1)

R. Gaska, J. W. Yang, A. Osinsky, Q. Chen, M. A. Khan, A. O. Orlov, G. L. Snider, and M. S. Shur, "Electron transport in AlGaN-GaN heterostructures grown on 6H-SiC substrates," Appl. Phys. Lett. 72, 707-709 (1998).
[CrossRef]

1997 (3)

T. I. Jeon, and D. Grischkowsky, "Nature of conduction in doped silicon," Phys. Rev. Lett. 78, 1106-1109 (1997).
[CrossRef]

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, Y. Sugimoto, and H. Kiyoku, "Room-temperature continuous-wave operation of InGaN multi-quantum-well structure laser diodes with a lifetime of 27 hours," Appl. Phys. Lett. 70, 1417-1419 (1997).
[CrossRef]

F. A. Ponce, and D. P. Bour, "NItride-based semiconductors for blue and green light-emitting devices," Nature 386, 351-359, (1997).
[CrossRef]

1996 (3)

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, H. Kiyoku, and Y. Sugimoto, "InGaN-based multi-quantum-well-structure laser diodes," Jpn. J. Appl. Phys.,  35, L74-L76 (1996).
[CrossRef]

D. D. Chen, M. Smith, J. Y. Lin, H. X. Jiang, S. H. Wei, M. A. Khan, and C. J. Sun, "Fundamental optical transitions in GaN," Appl. Phys. Lett. 68, 2784-2786 (1996).
[CrossRef]

K. T. Tsen, R. P. Joshi, D. K. Ferry, A. Botchkarev, B. Sverdlov, A. Salvador, and H. Morkoc, "Nonequilibrium electron distributions and phonon dynamics in wurtzite GaN," Appl. Phys. Lett. 68, 2990-2992 (1996).
[CrossRef]

1994 (3)

T. P. Chow, and R. Tyagi, "Wide bandgap compound semiconductors for superior high-voltage unipolar power devices," IEEE Trans. Electron. Dev. 41, 1481-1483 (1994).
[CrossRef]

H. Morkoc, S. Strite, G. B. Gao, M. E. Lin, B. Sverdlov, and M. Burns, "Large-band-gap SiC, III-V nitride, and II-VI ZnSe-based semiconductor device technologies," J. Appl. Phys. 76, 1363-1398 (1994).
[CrossRef]

S. Nakamura, T. Mukai, and M. Senoh, "Femtochemistry: Atomic-Scale Dynamics of the Chemical Bond," Appl. Phys. Lett. 64, 1687-1689 (1994).
[CrossRef]

1991 (1)

F. Alvarez, A. Alegria, and J. Colmenero, "Relationship between the time-domain Kohlrausch-Williams-Watts and frequency-domain Havriliak-Negami relaxation functions," Phys. Rev. B 44, 7306-7312 (1991).
[CrossRef]

1990 (1)

1980 (1)

C. P. Lindsey and G. D. Patterson, "Detailed comparison of the Williams-Watts and Cole-Davidson functions," J. Chem. Phys. 73, 3348-3357 (1980).
[CrossRef]

1973 (1)

A. S. Barker, Jr. and M. Ilegems, "Infrared Lattice Vibrations and Free-Electron Dispersion in GaN," Phys. Rev. B 7, 743-750 (1973).
[CrossRef]

1970 (1)

G. Williams and D. C. Watts, "Non-Symmetrical Dielectric Relaxation Behaviour Arising from a Simple Empirical Decay Function," Trans. Faraday Soc. 66, 80-85 (1970).
[CrossRef]

1951 (1)

D. W. Davidson and R. H. Cole, "Dielectric Relaxation in Glycerol, Propylene Glycol, and n-Propanol," J. Chem. Phys. 19, 1484-1490 (1951).
[CrossRef]

Alegria, A.

M. Tyagi, A. Alegria, and J. Colmenero, "Heterogeneous dynamics of poly(vinyl acetate) far above Tg:A combined study by dielectric spectroscopy and quasielastic neutron scattering," J. Chem. Phys. 122, 2449091-24490913 (2005).
[CrossRef]

F. Alvarez, A. Alegria, and J. Colmenero, "Relationship between the time-domain Kohlrausch-Williams-Watts and frequency-domain Havriliak-Negami relaxation functions," Phys. Rev. B 44, 7306-7312 (1991).
[CrossRef]

Alvarez, F.

F. Alvarez, A. Alegria, and J. Colmenero, "Relationship between the time-domain Kohlrausch-Williams-Watts and frequency-domain Havriliak-Negami relaxation functions," Phys. Rev. B 44, 7306-7312 (1991).
[CrossRef]

Armour, E. A.

D. I. Florescu, J. C. Ramer, D. S. Lee, and E. A. Armour, "InGaN/GaN single-quantum-well light-emitting diodes optical output efficiency dependence on the properties of the barrier layer separating the active and p-layer regions," Appl. Phys. Lett. 84, 5252-5254 (2004).
[CrossRef]

Azad, A. K.

W. Zhang, A. K. Azad, and D. Grischkowsky, "Terahertz studies of carrier dynamics and dielectric response of n-type, freestanding epitaxial GaN," Appl. Phys. Lett. 82, 2841-2843 (2003).
[CrossRef]

Barker, A. S.

A. S. Barker, Jr. and M. Ilegems, "Infrared Lattice Vibrations and Free-Electron Dispersion in GaN," Phys. Rev. B 7, 743-750 (1973).
[CrossRef]

Beard, M. C.

M. C. Beard, G. M. Turner, and C. A. Schmuttenmaer, "Transient photoconductivity in GaAs as measured by time-resolved terahertz spectroscopy," Phys. Rev. B 62, 15764-15777 (2000).
[CrossRef]

Botchkarev, A.

K. T. Tsen, R. P. Joshi, D. K. Ferry, A. Botchkarev, B. Sverdlov, A. Salvador, and H. Morkoc, "Nonequilibrium electron distributions and phonon dynamics in wurtzite GaN," Appl. Phys. Lett. 68, 2990-2992 (1996).
[CrossRef]

Bour, D. P.

F. A. Ponce, and D. P. Bour, "NItride-based semiconductors for blue and green light-emitting devices," Nature 386, 351-359, (1997).
[CrossRef]

Burns, M.

H. Morkoc, S. Strite, G. B. Gao, M. E. Lin, B. Sverdlov, and M. Burns, "Large-band-gap SiC, III-V nitride, and II-VI ZnSe-based semiconductor device technologies," J. Appl. Phys. 76, 1363-1398 (1994).
[CrossRef]

Cao, X. A.

X. A. Cao, J. M. Teetsov, M. P. D'Evelyn, D. W. Merfeld, and C. H. Yan, "Electrical characteristics of InGaN/GaN light-emitting diodes grown on GaN and sapphire substrates," Appl. Phys. Lett. 85, 7-9 (2004).
[CrossRef]

Chang, S. J.

K. S. Ramaiah, Y. K. Su, S. J. Chang, B. Kerr, H. P. Liu, and I. G. Chen, "Characterization of InGaN/GaN multi-quantum-well blue-light-emitting diodes grown by metal organic chemical vapor deposition," Appl. Phys. Lett. 84, 3307-3309 (2004).
[CrossRef]

Chen, D. D.

D. D. Chen, M. Smith, J. Y. Lin, H. X. Jiang, S. H. Wei, M. A. Khan, and C. J. Sun, "Fundamental optical transitions in GaN," Appl. Phys. Lett. 68, 2784-2786 (1996).
[CrossRef]

Chen, I. G.

K. S. Ramaiah, Y. K. Su, S. J. Chang, B. Kerr, H. P. Liu, and I. G. Chen, "Characterization of InGaN/GaN multi-quantum-well blue-light-emitting diodes grown by metal organic chemical vapor deposition," Appl. Phys. Lett. 84, 3307-3309 (2004).
[CrossRef]

Chen, Q.

R. Gaska, J. W. Yang, A. Osinsky, Q. Chen, M. A. Khan, A. O. Orlov, G. L. Snider, and M. S. Shur, "Electron transport in AlGaN-GaN heterostructures grown on 6H-SiC substrates," Appl. Phys. Lett. 72, 707-709 (1998).
[CrossRef]

Chow, T. P.

T. P. Chow, and R. Tyagi, "Wide bandgap compound semiconductors for superior high-voltage unipolar power devices," IEEE Trans. Electron. Dev. 41, 1481-1483 (1994).
[CrossRef]

Cole, R. H.

D. W. Davidson and R. H. Cole, "Dielectric Relaxation in Glycerol, Propylene Glycol, and n-Propanol," J. Chem. Phys. 19, 1484-1490 (1951).
[CrossRef]

Collins, T. C.

D. C. Reynolds, B. Jogai, and T. C. Collins, "Longitudinal Excitons in GaN," Appl. Phys. Lett. 80, 3928-3930 (2002).
[CrossRef]

Colmenero, J.

M. Tyagi, A. Alegria, and J. Colmenero, "Heterogeneous dynamics of poly(vinyl acetate) far above Tg:A combined study by dielectric spectroscopy and quasielastic neutron scattering," J. Chem. Phys. 122, 2449091-24490913 (2005).
[CrossRef]

F. Alvarez, A. Alegria, and J. Colmenero, "Relationship between the time-domain Kohlrausch-Williams-Watts and frequency-domain Havriliak-Negami relaxation functions," Phys. Rev. B 44, 7306-7312 (1991).
[CrossRef]

Darvish, S. R.

A. Yasan, R. McClintock, K. Mayes, S. R. Darvish, H. Zhang, P. Kung, M. Razeghi, S. K. Lee, and J. Y. Han, "Comparison of ultraviolet light-emitting diodes with peak emission at 340 nm grown on GaN substrate and sapphire," Appl. Phys. Lett. 81, 2151-2153 (2002).
[CrossRef]

Davidson, D. W.

D. W. Davidson and R. H. Cole, "Dielectric Relaxation in Glycerol, Propylene Glycol, and n-Propanol," J. Chem. Phys. 19, 1484-1490 (1951).
[CrossRef]

D'Evelyn, M. P.

X. A. Cao, J. M. Teetsov, M. P. D'Evelyn, D. W. Merfeld, and C. H. Yan, "Electrical characteristics of InGaN/GaN light-emitting diodes grown on GaN and sapphire substrates," Appl. Phys. Lett. 85, 7-9 (2004).
[CrossRef]

Einfeldt, S.

A. Kasic, M. Schubert, S. Einfeldt, D. Hommel, and T. E. Tiwald, "Free-carrier and phonon properties of n- and p-type hexagonal GaN films measured by infrared ellipsometry," Phys. Rev. B 62, 7365-7377 (2000).
[CrossRef]

Fattinger, Ch.

Ferry, D. K.

K. T. Tsen, R. P. Joshi, D. K. Ferry, A. Botchkarev, B. Sverdlov, A. Salvador, and H. Morkoc, "Nonequilibrium electron distributions and phonon dynamics in wurtzite GaN," Appl. Phys. Lett. 68, 2990-2992 (1996).
[CrossRef]

Florescu, D. I.

D. I. Florescu, J. C. Ramer, D. S. Lee, and E. A. Armour, "InGaN/GaN single-quantum-well light-emitting diodes optical output efficiency dependence on the properties of the barrier layer separating the active and p-layer regions," Appl. Phys. Lett. 84, 5252-5254 (2004).
[CrossRef]

Freitas, J. A.

W. J. Moore, J. A. Freitas, Jr., S. K. Lee, S. S. Park, and J. Y. Han, "Magneto-optical studies of free-standing hydride-vapor-phase epitaxial GaN," Phys. Rev. B 65, 081201 (2002).
[CrossRef]

Gao, G. B.

H. Morkoc, S. Strite, G. B. Gao, M. E. Lin, B. Sverdlov, and M. Burns, "Large-band-gap SiC, III-V nitride, and II-VI ZnSe-based semiconductor device technologies," J. Appl. Phys. 76, 1363-1398 (1994).
[CrossRef]

Gaska, R.

R. Gaska, J. W. Yang, A. Osinsky, Q. Chen, M. A. Khan, A. O. Orlov, G. L. Snider, and M. S. Shur, "Electron transport in AlGaN-GaN heterostructures grown on 6H-SiC substrates," Appl. Phys. Lett. 72, 707-709 (1998).
[CrossRef]

Grischkowsky, D.

W. Zhang, A. K. Azad, and D. Grischkowsky, "Terahertz studies of carrier dynamics and dielectric response of n-type, freestanding epitaxial GaN," Appl. Phys. Lett. 82, 2841-2843 (2003).
[CrossRef]

T. I. Jeon, and D. Grischkowsky, "Nature of conduction in doped silicon," Phys. Rev. Lett. 78, 1106-1109 (1997).
[CrossRef]

D. Grischkowsky, S. R. Keiding, M. van Exter, and Ch. Fattinger, "Far-infrared time-domain spectroscopy with terahertz beams of dielectrics and semiconductors," J. Opt. Soc. Am. B 7, 2006-2015 (1990).
[CrossRef]

Hahn, J. Y.

D. C. Reynolds, D. C. Look, B. Jogai, A. W. Saxler, S. S. Park, and J. Y. Hahn, "A giant magnetoresistance sensor for high magnetic field measurements," Appl. Phys. Lett. 77, 1879-1881 (2000).
[CrossRef]

Han, J. Y.

W. J. Moore, J. A. Freitas, Jr., S. K. Lee, S. S. Park, and J. Y. Han, "Magneto-optical studies of free-standing hydride-vapor-phase epitaxial GaN," Phys. Rev. B 65, 081201 (2002).
[CrossRef]

A. Yasan, R. McClintock, K. Mayes, S. R. Darvish, H. Zhang, P. Kung, M. Razeghi, S. K. Lee, and J. Y. Han, "Comparison of ultraviolet light-emitting diodes with peak emission at 340 nm grown on GaN substrate and sapphire," Appl. Phys. Lett. 81, 2151-2153 (2002).
[CrossRef]

Hangyo, M.

T. Nagashima, K. Takata, S. Nashima, H. Harima, and M. Hangyo, "measurement of electrical properties of GaN thin films using terahertz-time domain spectroscopy," Jpn. J. Appl. Phys.,  44, 926-931 (2005).
[CrossRef]

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T. Nagashima, K. Takata, S. Nashima, H. Harima, and M. Hangyo, "measurement of electrical properties of GaN thin films using terahertz-time domain spectroscopy," Jpn. J. Appl. Phys.,  44, 926-931 (2005).
[CrossRef]

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A. Kasic, M. Schubert, S. Einfeldt, D. Hommel, and T. E. Tiwald, "Free-carrier and phonon properties of n- and p-type hexagonal GaN films measured by infrared ellipsometry," Phys. Rev. B 62, 7365-7377 (2000).
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S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, Y. Sugimoto, and H. Kiyoku, "Room-temperature continuous-wave operation of InGaN multi-quantum-well structure laser diodes with a lifetime of 27 hours," Appl. Phys. Lett. 70, 1417-1419 (1997).
[CrossRef]

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, H. Kiyoku, and Y. Sugimoto, "InGaN-based multi-quantum-well-structure laser diodes," Jpn. J. Appl. Phys.,  35, L74-L76 (1996).
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D. D. Chen, M. Smith, J. Y. Lin, H. X. Jiang, S. H. Wei, M. A. Khan, and C. J. Sun, "Fundamental optical transitions in GaN," Appl. Phys. Lett. 68, 2784-2786 (1996).
[CrossRef]

Jogai, B.

D. C. Reynolds, B. Jogai, and T. C. Collins, "Longitudinal Excitons in GaN," Appl. Phys. Lett. 80, 3928-3930 (2002).
[CrossRef]

D. C. Reynolds, D. C. Look, B. Jogai, A. W. Saxler, S. S. Park, and J. Y. Hahn, "A giant magnetoresistance sensor for high magnetic field measurements," Appl. Phys. Lett. 77, 1879-1881 (2000).
[CrossRef]

Joshi, R. P.

K. T. Tsen, R. P. Joshi, D. K. Ferry, A. Botchkarev, B. Sverdlov, A. Salvador, and H. Morkoc, "Nonequilibrium electron distributions and phonon dynamics in wurtzite GaN," Appl. Phys. Lett. 68, 2990-2992 (1996).
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A. Kasic, M. Schubert, S. Einfeldt, D. Hommel, and T. E. Tiwald, "Free-carrier and phonon properties of n- and p-type hexagonal GaN films measured by infrared ellipsometry," Phys. Rev. B 62, 7365-7377 (2000).
[CrossRef]

Keiding, S. R.

Kerr, B.

K. S. Ramaiah, Y. K. Su, S. J. Chang, B. Kerr, H. P. Liu, and I. G. Chen, "Characterization of InGaN/GaN multi-quantum-well blue-light-emitting diodes grown by metal organic chemical vapor deposition," Appl. Phys. Lett. 84, 3307-3309 (2004).
[CrossRef]

Khan, M. A.

R. Gaska, J. W. Yang, A. Osinsky, Q. Chen, M. A. Khan, A. O. Orlov, G. L. Snider, and M. S. Shur, "Electron transport in AlGaN-GaN heterostructures grown on 6H-SiC substrates," Appl. Phys. Lett. 72, 707-709 (1998).
[CrossRef]

D. D. Chen, M. Smith, J. Y. Lin, H. X. Jiang, S. H. Wei, M. A. Khan, and C. J. Sun, "Fundamental optical transitions in GaN," Appl. Phys. Lett. 68, 2784-2786 (1996).
[CrossRef]

Kiyoku, H.

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, Y. Sugimoto, and H. Kiyoku, "Room-temperature continuous-wave operation of InGaN multi-quantum-well structure laser diodes with a lifetime of 27 hours," Appl. Phys. Lett. 70, 1417-1419 (1997).
[CrossRef]

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, H. Kiyoku, and Y. Sugimoto, "InGaN-based multi-quantum-well-structure laser diodes," Jpn. J. Appl. Phys.,  35, L74-L76 (1996).
[CrossRef]

Kung, P.

A. Yasan, R. McClintock, K. Mayes, S. R. Darvish, H. Zhang, P. Kung, M. Razeghi, S. K. Lee, and J. Y. Han, "Comparison of ultraviolet light-emitting diodes with peak emission at 340 nm grown on GaN substrate and sapphire," Appl. Phys. Lett. 81, 2151-2153 (2002).
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D. I. Florescu, J. C. Ramer, D. S. Lee, and E. A. Armour, "InGaN/GaN single-quantum-well light-emitting diodes optical output efficiency dependence on the properties of the barrier layer separating the active and p-layer regions," Appl. Phys. Lett. 84, 5252-5254 (2004).
[CrossRef]

Lee, S. K.

A. Yasan, R. McClintock, K. Mayes, S. R. Darvish, H. Zhang, P. Kung, M. Razeghi, S. K. Lee, and J. Y. Han, "Comparison of ultraviolet light-emitting diodes with peak emission at 340 nm grown on GaN substrate and sapphire," Appl. Phys. Lett. 81, 2151-2153 (2002).
[CrossRef]

W. J. Moore, J. A. Freitas, Jr., S. K. Lee, S. S. Park, and J. Y. Han, "Magneto-optical studies of free-standing hydride-vapor-phase epitaxial GaN," Phys. Rev. B 65, 081201 (2002).
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Lin, J. Y.

D. D. Chen, M. Smith, J. Y. Lin, H. X. Jiang, S. H. Wei, M. A. Khan, and C. J. Sun, "Fundamental optical transitions in GaN," Appl. Phys. Lett. 68, 2784-2786 (1996).
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Lin, M. E.

H. Morkoc, S. Strite, G. B. Gao, M. E. Lin, B. Sverdlov, and M. Burns, "Large-band-gap SiC, III-V nitride, and II-VI ZnSe-based semiconductor device technologies," J. Appl. Phys. 76, 1363-1398 (1994).
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C. P. Lindsey and G. D. Patterson, "Detailed comparison of the Williams-Watts and Cole-Davidson functions," J. Chem. Phys. 73, 3348-3357 (1980).
[CrossRef]

Liu, H. P.

K. S. Ramaiah, Y. K. Su, S. J. Chang, B. Kerr, H. P. Liu, and I. G. Chen, "Characterization of InGaN/GaN multi-quantum-well blue-light-emitting diodes grown by metal organic chemical vapor deposition," Appl. Phys. Lett. 84, 3307-3309 (2004).
[CrossRef]

Look, D. C.

D. C. Reynolds, D. C. Look, B. Jogai, A. W. Saxler, S. S. Park, and J. Y. Hahn, "A giant magnetoresistance sensor for high magnetic field measurements," Appl. Phys. Lett. 77, 1879-1881 (2000).
[CrossRef]

Matsushita, T.

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, Y. Sugimoto, and H. Kiyoku, "Room-temperature continuous-wave operation of InGaN multi-quantum-well structure laser diodes with a lifetime of 27 hours," Appl. Phys. Lett. 70, 1417-1419 (1997).
[CrossRef]

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, H. Kiyoku, and Y. Sugimoto, "InGaN-based multi-quantum-well-structure laser diodes," Jpn. J. Appl. Phys.,  35, L74-L76 (1996).
[CrossRef]

Mayes, K.

A. Yasan, R. McClintock, K. Mayes, S. R. Darvish, H. Zhang, P. Kung, M. Razeghi, S. K. Lee, and J. Y. Han, "Comparison of ultraviolet light-emitting diodes with peak emission at 340 nm grown on GaN substrate and sapphire," Appl. Phys. Lett. 81, 2151-2153 (2002).
[CrossRef]

McClintock, R.

A. Yasan, R. McClintock, K. Mayes, S. R. Darvish, H. Zhang, P. Kung, M. Razeghi, S. K. Lee, and J. Y. Han, "Comparison of ultraviolet light-emitting diodes with peak emission at 340 nm grown on GaN substrate and sapphire," Appl. Phys. Lett. 81, 2151-2153 (2002).
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Merfeld, D. W.

X. A. Cao, J. M. Teetsov, M. P. D'Evelyn, D. W. Merfeld, and C. H. Yan, "Electrical characteristics of InGaN/GaN light-emitting diodes grown on GaN and sapphire substrates," Appl. Phys. Lett. 85, 7-9 (2004).
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Moore, W. J.

W. J. Moore, J. A. Freitas, Jr., S. K. Lee, S. S. Park, and J. Y. Han, "Magneto-optical studies of free-standing hydride-vapor-phase epitaxial GaN," Phys. Rev. B 65, 081201 (2002).
[CrossRef]

Morkoc, H.

K. T. Tsen, R. P. Joshi, D. K. Ferry, A. Botchkarev, B. Sverdlov, A. Salvador, and H. Morkoc, "Nonequilibrium electron distributions and phonon dynamics in wurtzite GaN," Appl. Phys. Lett. 68, 2990-2992 (1996).
[CrossRef]

H. Morkoc, S. Strite, G. B. Gao, M. E. Lin, B. Sverdlov, and M. Burns, "Large-band-gap SiC, III-V nitride, and II-VI ZnSe-based semiconductor device technologies," J. Appl. Phys. 76, 1363-1398 (1994).
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S. Nakamura, T. Mukai, and M. Senoh, "Femtochemistry: Atomic-Scale Dynamics of the Chemical Bond," Appl. Phys. Lett. 64, 1687-1689 (1994).
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S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, Y. Sugimoto, and H. Kiyoku, "Room-temperature continuous-wave operation of InGaN multi-quantum-well structure laser diodes with a lifetime of 27 hours," Appl. Phys. Lett. 70, 1417-1419 (1997).
[CrossRef]

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, H. Kiyoku, and Y. Sugimoto, "InGaN-based multi-quantum-well-structure laser diodes," Jpn. J. Appl. Phys.,  35, L74-L76 (1996).
[CrossRef]

Nagashima, T.

T. Nagashima, K. Takata, S. Nashima, H. Harima, and M. Hangyo, "measurement of electrical properties of GaN thin films using terahertz-time domain spectroscopy," Jpn. J. Appl. Phys.,  44, 926-931 (2005).
[CrossRef]

Nakamura, S.

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, Y. Sugimoto, and H. Kiyoku, "Room-temperature continuous-wave operation of InGaN multi-quantum-well structure laser diodes with a lifetime of 27 hours," Appl. Phys. Lett. 70, 1417-1419 (1997).
[CrossRef]

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, H. Kiyoku, and Y. Sugimoto, "InGaN-based multi-quantum-well-structure laser diodes," Jpn. J. Appl. Phys.,  35, L74-L76 (1996).
[CrossRef]

S. Nakamura, T. Mukai, and M. Senoh, "Femtochemistry: Atomic-Scale Dynamics of the Chemical Bond," Appl. Phys. Lett. 64, 1687-1689 (1994).
[CrossRef]

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T. Nagashima, K. Takata, S. Nashima, H. Harima, and M. Hangyo, "measurement of electrical properties of GaN thin films using terahertz-time domain spectroscopy," Jpn. J. Appl. Phys.,  44, 926-931 (2005).
[CrossRef]

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R. Gaska, J. W. Yang, A. Osinsky, Q. Chen, M. A. Khan, A. O. Orlov, G. L. Snider, and M. S. Shur, "Electron transport in AlGaN-GaN heterostructures grown on 6H-SiC substrates," Appl. Phys. Lett. 72, 707-709 (1998).
[CrossRef]

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R. Gaska, J. W. Yang, A. Osinsky, Q. Chen, M. A. Khan, A. O. Orlov, G. L. Snider, and M. S. Shur, "Electron transport in AlGaN-GaN heterostructures grown on 6H-SiC substrates," Appl. Phys. Lett. 72, 707-709 (1998).
[CrossRef]

Park, S. S.

W. J. Moore, J. A. Freitas, Jr., S. K. Lee, S. S. Park, and J. Y. Han, "Magneto-optical studies of free-standing hydride-vapor-phase epitaxial GaN," Phys. Rev. B 65, 081201 (2002).
[CrossRef]

D. C. Reynolds, D. C. Look, B. Jogai, A. W. Saxler, S. S. Park, and J. Y. Hahn, "A giant magnetoresistance sensor for high magnetic field measurements," Appl. Phys. Lett. 77, 1879-1881 (2000).
[CrossRef]

Patterson, G. D.

C. P. Lindsey and G. D. Patterson, "Detailed comparison of the Williams-Watts and Cole-Davidson functions," J. Chem. Phys. 73, 3348-3357 (1980).
[CrossRef]

Pearton, S. J.

S. J. Pearton, J. C. Zolper, R. J. Shul, and F. Ren, "GaN: Processing, defects, and devices," J. Appl. Phys. 86, 1-78 (1999).
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F. A. Ponce, and D. P. Bour, "NItride-based semiconductors for blue and green light-emitting devices," Nature 386, 351-359, (1997).
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K. S. Ramaiah, Y. K. Su, S. J. Chang, B. Kerr, H. P. Liu, and I. G. Chen, "Characterization of InGaN/GaN multi-quantum-well blue-light-emitting diodes grown by metal organic chemical vapor deposition," Appl. Phys. Lett. 84, 3307-3309 (2004).
[CrossRef]

Ramer, J. C.

D. I. Florescu, J. C. Ramer, D. S. Lee, and E. A. Armour, "InGaN/GaN single-quantum-well light-emitting diodes optical output efficiency dependence on the properties of the barrier layer separating the active and p-layer regions," Appl. Phys. Lett. 84, 5252-5254 (2004).
[CrossRef]

Razeghi, M.

A. Yasan, R. McClintock, K. Mayes, S. R. Darvish, H. Zhang, P. Kung, M. Razeghi, S. K. Lee, and J. Y. Han, "Comparison of ultraviolet light-emitting diodes with peak emission at 340 nm grown on GaN substrate and sapphire," Appl. Phys. Lett. 81, 2151-2153 (2002).
[CrossRef]

Ren, F.

S. J. Pearton, J. C. Zolper, R. J. Shul, and F. Ren, "GaN: Processing, defects, and devices," J. Appl. Phys. 86, 1-78 (1999).
[CrossRef]

Reynolds, D. C.

D. C. Reynolds, B. Jogai, and T. C. Collins, "Longitudinal Excitons in GaN," Appl. Phys. Lett. 80, 3928-3930 (2002).
[CrossRef]

D. C. Reynolds, D. C. Look, B. Jogai, A. W. Saxler, S. S. Park, and J. Y. Hahn, "A giant magnetoresistance sensor for high magnetic field measurements," Appl. Phys. Lett. 77, 1879-1881 (2000).
[CrossRef]

Salvador, A.

K. T. Tsen, R. P. Joshi, D. K. Ferry, A. Botchkarev, B. Sverdlov, A. Salvador, and H. Morkoc, "Nonequilibrium electron distributions and phonon dynamics in wurtzite GaN," Appl. Phys. Lett. 68, 2990-2992 (1996).
[CrossRef]

Saxler, A. W.

D. C. Reynolds, D. C. Look, B. Jogai, A. W. Saxler, S. S. Park, and J. Y. Hahn, "A giant magnetoresistance sensor for high magnetic field measurements," Appl. Phys. Lett. 77, 1879-1881 (2000).
[CrossRef]

Schmuttenmaer, C. A.

M. C. Beard, G. M. Turner, and C. A. Schmuttenmaer, "Transient photoconductivity in GaAs as measured by time-resolved terahertz spectroscopy," Phys. Rev. B 62, 15764-15777 (2000).
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Schubert, M.

A. Kasic, M. Schubert, S. Einfeldt, D. Hommel, and T. E. Tiwald, "Free-carrier and phonon properties of n- and p-type hexagonal GaN films measured by infrared ellipsometry," Phys. Rev. B 62, 7365-7377 (2000).
[CrossRef]

Senoh, M.

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, Y. Sugimoto, and H. Kiyoku, "Room-temperature continuous-wave operation of InGaN multi-quantum-well structure laser diodes with a lifetime of 27 hours," Appl. Phys. Lett. 70, 1417-1419 (1997).
[CrossRef]

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, H. Kiyoku, and Y. Sugimoto, "InGaN-based multi-quantum-well-structure laser diodes," Jpn. J. Appl. Phys.,  35, L74-L76 (1996).
[CrossRef]

S. Nakamura, T. Mukai, and M. Senoh, "Femtochemistry: Atomic-Scale Dynamics of the Chemical Bond," Appl. Phys. Lett. 64, 1687-1689 (1994).
[CrossRef]

Shul, R. J.

S. J. Pearton, J. C. Zolper, R. J. Shul, and F. Ren, "GaN: Processing, defects, and devices," J. Appl. Phys. 86, 1-78 (1999).
[CrossRef]

Shur, M. S.

R. Gaska, J. W. Yang, A. Osinsky, Q. Chen, M. A. Khan, A. O. Orlov, G. L. Snider, and M. S. Shur, "Electron transport in AlGaN-GaN heterostructures grown on 6H-SiC substrates," Appl. Phys. Lett. 72, 707-709 (1998).
[CrossRef]

Smith, M.

D. D. Chen, M. Smith, J. Y. Lin, H. X. Jiang, S. H. Wei, M. A. Khan, and C. J. Sun, "Fundamental optical transitions in GaN," Appl. Phys. Lett. 68, 2784-2786 (1996).
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N. V. Smith, "Classical generalization of the Drude formula for the optical conductivity," Phys. Rev. B 64, 155106 (2001).
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R. Gaska, J. W. Yang, A. Osinsky, Q. Chen, M. A. Khan, A. O. Orlov, G. L. Snider, and M. S. Shur, "Electron transport in AlGaN-GaN heterostructures grown on 6H-SiC substrates," Appl. Phys. Lett. 72, 707-709 (1998).
[CrossRef]

Strite, S.

H. Morkoc, S. Strite, G. B. Gao, M. E. Lin, B. Sverdlov, and M. Burns, "Large-band-gap SiC, III-V nitride, and II-VI ZnSe-based semiconductor device technologies," J. Appl. Phys. 76, 1363-1398 (1994).
[CrossRef]

Su, Y. K.

K. S. Ramaiah, Y. K. Su, S. J. Chang, B. Kerr, H. P. Liu, and I. G. Chen, "Characterization of InGaN/GaN multi-quantum-well blue-light-emitting diodes grown by metal organic chemical vapor deposition," Appl. Phys. Lett. 84, 3307-3309 (2004).
[CrossRef]

Sugimoto, Y.

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, Y. Sugimoto, and H. Kiyoku, "Room-temperature continuous-wave operation of InGaN multi-quantum-well structure laser diodes with a lifetime of 27 hours," Appl. Phys. Lett. 70, 1417-1419 (1997).
[CrossRef]

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, H. Kiyoku, and Y. Sugimoto, "InGaN-based multi-quantum-well-structure laser diodes," Jpn. J. Appl. Phys.,  35, L74-L76 (1996).
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Sun, C. J.

D. D. Chen, M. Smith, J. Y. Lin, H. X. Jiang, S. H. Wei, M. A. Khan, and C. J. Sun, "Fundamental optical transitions in GaN," Appl. Phys. Lett. 68, 2784-2786 (1996).
[CrossRef]

Sverdlov, B.

K. T. Tsen, R. P. Joshi, D. K. Ferry, A. Botchkarev, B. Sverdlov, A. Salvador, and H. Morkoc, "Nonequilibrium electron distributions and phonon dynamics in wurtzite GaN," Appl. Phys. Lett. 68, 2990-2992 (1996).
[CrossRef]

H. Morkoc, S. Strite, G. B. Gao, M. E. Lin, B. Sverdlov, and M. Burns, "Large-band-gap SiC, III-V nitride, and II-VI ZnSe-based semiconductor device technologies," J. Appl. Phys. 76, 1363-1398 (1994).
[CrossRef]

Takata, K.

T. Nagashima, K. Takata, S. Nashima, H. Harima, and M. Hangyo, "measurement of electrical properties of GaN thin films using terahertz-time domain spectroscopy," Jpn. J. Appl. Phys.,  44, 926-931 (2005).
[CrossRef]

Teetsov, J. M.

X. A. Cao, J. M. Teetsov, M. P. D'Evelyn, D. W. Merfeld, and C. H. Yan, "Electrical characteristics of InGaN/GaN light-emitting diodes grown on GaN and sapphire substrates," Appl. Phys. Lett. 85, 7-9 (2004).
[CrossRef]

Tiwald, T. E.

A. Kasic, M. Schubert, S. Einfeldt, D. Hommel, and T. E. Tiwald, "Free-carrier and phonon properties of n- and p-type hexagonal GaN films measured by infrared ellipsometry," Phys. Rev. B 62, 7365-7377 (2000).
[CrossRef]

Tsen, K. T.

K. T. Tsen, R. P. Joshi, D. K. Ferry, A. Botchkarev, B. Sverdlov, A. Salvador, and H. Morkoc, "Nonequilibrium electron distributions and phonon dynamics in wurtzite GaN," Appl. Phys. Lett. 68, 2990-2992 (1996).
[CrossRef]

Turner, G. M.

M. C. Beard, G. M. Turner, and C. A. Schmuttenmaer, "Transient photoconductivity in GaAs as measured by time-resolved terahertz spectroscopy," Phys. Rev. B 62, 15764-15777 (2000).
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M. Tyagi, A. Alegria, and J. Colmenero, "Heterogeneous dynamics of poly(vinyl acetate) far above Tg:A combined study by dielectric spectroscopy and quasielastic neutron scattering," J. Chem. Phys. 122, 2449091-24490913 (2005).
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G. Williams and D. C. Watts, "Non-Symmetrical Dielectric Relaxation Behaviour Arising from a Simple Empirical Decay Function," Trans. Faraday Soc. 66, 80-85 (1970).
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Wei, S. H.

D. D. Chen, M. Smith, J. Y. Lin, H. X. Jiang, S. H. Wei, M. A. Khan, and C. J. Sun, "Fundamental optical transitions in GaN," Appl. Phys. Lett. 68, 2784-2786 (1996).
[CrossRef]

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G. Williams and D. C. Watts, "Non-Symmetrical Dielectric Relaxation Behaviour Arising from a Simple Empirical Decay Function," Trans. Faraday Soc. 66, 80-85 (1970).
[CrossRef]

Yamada, T.

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, Y. Sugimoto, and H. Kiyoku, "Room-temperature continuous-wave operation of InGaN multi-quantum-well structure laser diodes with a lifetime of 27 hours," Appl. Phys. Lett. 70, 1417-1419 (1997).
[CrossRef]

S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, H. Kiyoku, and Y. Sugimoto, "InGaN-based multi-quantum-well-structure laser diodes," Jpn. J. Appl. Phys.,  35, L74-L76 (1996).
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Figures (5)

Fig. 1.
Fig. 1.

n1, n, and n3 are the refractive indices. E0(ω) is the incident THz field, and Eref(ω) and Efilm(ω) are the reference (substrate only) and signal (with the film) THz fields, respectively. d is the thickness of the film.

Fig. 2.
Fig. 2.

The experimental setup of the THz spectrometer.

Fig. 3.
Fig. 3.

Measured THz pulses of the reference and signal.

Fig. 4.
Fig. 4.

(a) Plot of the measured the indices of refraction, on a logarithmic scale, for the GaN film. (b) The measured the extinction coefficients, on a logarithmic scale, for GaN film. (c) The measured the real conductivities, on a logarithmic scale, for the GaN film. (d) The measured the imaginary conductivities, on a logarithmic scale, for the GaN film. (--- dash) Fit to the simple Drude model; (... dot) Fit to the Cole-Davidson model; (- solid) Fit to the stretched exponential model.

Fig. 5.
Fig. 5.

Plot of the stretched exponential distribution function against log10(τ/τk ) using β=0.56 and τk =3.56×10-14 s.

Tables (1)

Tables Icon

Table 1. The fitting parameters for the measurements plotted in Fig. 4 and the results for Hall measurements.

Equations (17)

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E ref ( ω ) = t 13 E 0 ( ω ) exp ( i ω d c ) .
E film ( ω ) = t 12 t 23 exp ( in ω d c ) 1 r 21 r 23 exp [ i 2 n ω d c ] E 0 ( ω ) ,
E film ( ω ) E ref ( ω ) 1 + i ω d c ( n 1 + n 3 ) [ n 1 + n 1 n 3 + ( n 2 + i κ 2 ) 2 n 3 ] .
ε = c ω d ( n 1 + n 3 ) ρ sin Δ n 1 n 3 + n 1 + n 3 ,
ε = ( 1 ρ cos Δ ) c ω d ( n 1 + n 3 ) .
n 2 = 1 2 [ ε' + ε 2 + ε 2 ] 1 2 ,
κ 2 = 1 2 [ ε + ε 2 + ε 2 ] 1 2 ,
σ = ω ε 0 [ ε + i ( ε GaN ε ) ] .
ε = ε GaN + i σ ( ω ε 0 ) ,
σ ( ω ) = ε 0 ω p 2 τ 0 [ 1 ( i ω τ 0 ) α ] γ ,
g CD ( τ ) = sin π γ π ( τ τ 0 τ ) γ ,
τ = τ 0 γ .
γ = 1 0.812 ( 1 α ) 0.387 ,
β = ( α γ ) 0.813 ,
ln [ τ 0 τ k ] = 2.6 ( 1 β ) 0.5 exp ( 3 β ) .
g k ( τ ) = 1 π k = 0 ( 1 ) k k ! sin ( π β k ) Γ ( β k + 1 ) ( τ τ k ) β k + 1 .
τ = τ k β Γ ( 1 β ) .

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