Photoluminescence of the dominant deep-level acceptor in high-purity freestanding GaN is studied over a wide range of excitation intensities. A yellow luminescence (YL) band at about 2.2 eV saturates with increasing excitation intensity, whereas a green luminescence (GL) band at about 2.5 eV increases as a square of the excitation intensity. The YL and GL bands are attributed to two charge states of the same defect, presumably a gallium vacancy-oxygen complex.
REFERENCES
1.
2.
3.
T.
Suski
, P.
Perlin
, H.
Teisseyre
, M.
Leszczynski
, I.
Grzegory
, I.
Jun
, M.
Bockowski
, S.
Porowski
, and T. D.
Moustakas
, Appl. Phys. Lett.
67
, 2188
(1995
).4.
K.
Saarinen
, T.
Laine
, S.
Kuisma
, J.
Nissilä
, P.
Hautojärvi
, L.
Dobrzynski
, J. M.
Baranowski
, K.
Pakula
, R.
Stepniewski
, M.
Wojdak
, A.
Wysmolek
, T.
Suski
, M.
Leszczynski
, I.
Grzegory
, and S.
Porowski
, Phys. Rev. Lett.
79
, 3030
(1997
).5.
J.
Neugebauer
and C. G.
Van de Walle
, Appl. Phys. Lett.
69
, 503
(1996
).6.
7.
K.
Saarinen
, T.
Suski
, I.
Grzegory
, and D. C.
Look
, Phys. Rev. B
64
, 233201
(2001
).8.
M. A.
Reshchikov
, G.-C.
Yi
, and B. W.
Wessels
, Phys. Rev. B
59
, 13176
(1999
).9.
For deconvolution, we first neglected the contribution of the YL band at the highest and chose the initial shape of the GL band as the combined band shape at This band shape was deduced from the several spectra at low to obtain the shape of the YL band that enables us to fit the combined spectra at different with varying only intensities of the YL and GL bands. This procedure was repeated several times to achieve the best fit.
10.
M. A.
Reshchikov
and R. Y.
Korotkov
, Phys. Rev. B
64
, 115205
(2001
).11.
12.
D.
Huang
, F.
Yun
, P.
Visconti
, M. A.
Reshchikov
, D.
Wang
, H.
Morkoç
, D. L.
Rode
, L. A.
Farina
, Ç.
Kurdak
, K. T.
Tsen
, S. S.
Park
and K. Y.
Lee
, Solid-State Electron.
45
, 711
(2001
).13.
The excitation density was converted into generation rate by assuming that the effective thickness of the layer subjected to excitation was defined not by absorption coefficient but by diffusion length of holes in the studied sample. The hole diffusion length was taken as 1 μm.
14.
M. A.
Reshchikov
, H.
Morkoç
, S. S.
Park
, and K. Y.
Lee
, Appl. Phys. Lett.
78
, 2882
(2001
).15.
K. Saarinen (private communication).
16.
W.
Grieshaber
, E. F.
Schubert
, I. D.
Goepfert
, R. F.
Karlicek
, Jr., M. J.
Schurman
, and C.
Tran
, J. Appl. Phys.
80
, 4615
(1996
).17.
O.
Brandt
, H. J.
Wunsche
, H.
Yang
, R.
Klann
, H.-J.
Wüllhäuser
, and K. H.
Ploog
, J. Cryst. Growth
189/190
, 790
(1998
).18.
F.
Binet
, J. Y.
Duboz
, E.
Rosencher
, F.
Scholz
, and V.
Härle
, Appl. Phys. Lett.
69
, 1202
(1996
).19.
J.
Elsner
, R.
Jones
, M. I.
Heggie
, P. K.
Sitch
, M.
Haugk
, Th.
Frauenheim
, S.
Öberg
, and P. R.
Briddon
, Phys. Rev. B
58
, 12571
(1998
).20.
S. J.
Xu
, G.
Li
, S. J.
Chua
, X. C.
Wang
, and W.
Wang
, Appl. Phys. Lett.
72
, 2451
(1998
);S. A.
Brown
, R. J.
Reeves
, C. S.
Haase
, R.
Cheung
, C.
Kirchner
, and M.
Kamp
, Appl. Phys. Lett.
75
, 3285
(1999
).21.
M. A.
Reshchikov
, P.
Visconti
, and H.
Morkoç
, Appl. Phys. Lett.
78
, 177
(2001
).22.
M. A.
Reshchikov
, H.
Morkoç
, S. S.
Park
, and K. Y.
Lee
, Appl. Phys. Lett.
78
, 3041
(2001
).
This content is only available via PDF.
© 2002 American Institute of Physics.
2002
American Institute of Physics
You do not currently have access to this content.
