A theoretical study has been made to compare the quantum efficiencies of interwell and intrawell radiative transitions in quantum cascade lasers based on AlxGa1−xAs/GaAs technology. Radiative and nonradiative intersubband transition rates were calculated for a range of temperatures between 4 and 300 K at an applied electric field of 4 kV cm−1 for structures designed to emit in both mid-infrared and far-infrared frequency ranges. It is found that the internal quantum efficiency of mid-infrared devices is a maximum for diagonal, or interwell, transitions. Conversely, for the far-infrared devices, the quantum efficiency is a maximum for vertical, or intrawell, transitions.

Topics
Quantum efficiency, Lasers, Semiconductors
1.
J.
Faist
,
F.
Capasso
,
D. L.
Sivco
,
C.
Sirtori
,
A. L.
Hutchinson
, and
A. Y.
Cho
,
Science
264
,
553
(
1994
).
Google Scholar
 
2.
J.
Faist
,
F.
Capasso
,
D. L.
Sivco
,
C.
Sirtori
,
A. L.
Hutchinson
, and
A. Y.
Cho
,
Electron. Lett.
30
,
865
(
1994
).
Google Scholar
 
3.
C.
Sirtori
,
F.
Capasso
,
J.
Faist
,
D. L.
Sivco
,
A. L.
Hutchinson
, and
A. Y.
Cho
,
Appl. Phys. Lett.
66
,
4
(
1995
).
Google Scholar
 
4.
J.
Faist
,
F.
Capasso
,
C.
Sirtori
,
D. L.
Sivco
,
A. L.
Hutchinson
, and
A. Y.
Cho
,
Appl. Phys. Lett.
67
,
3057
(
1995
).
Google Scholar
 
5.
C.
Sirtori
,
J.
Faist
,
F.
Capasso
,
D. L.
Sivco
,
A. L.
Hutchinson
,
S. N. G.
Chu
, and
A. Y.
Cho
,
Appl. Phys. Lett.
68
,
1745
(
1996
).
Google Scholar
 
6.
J.
Faist
,
F.
Capasso
,
C.
Sirtori
,
D. L.
Sivco
,
A. L.
Hutchinson
, and
A. Y.
Cho
,
Appl. Phys. Lett.
66
,
538
(
1995
).
Google Scholar
 
7.
K.
Donovan
,
P.
Harrison
,
R. W.
Kelsall
, and
P.
Kinsler
,
Superlattices Microstruct.
25
,
373
(
1999
).
Google Scholar
 
8.
C.
Sirtori
,
P.
Kruck
,
S.
Barbieri
,
P.
Collot
,
J.
Nagle
,
M.
Beck
,
J.
Faist
, and
U.
Oesterle
,
Appl. Phys. Lett.
73
,
3486
(
1998
).
Google Scholar
 
9.
P. Harrison, Quantum Wells, Wires and Dots (Wiley, Chichester, 1999).
10.
S. M.
Goodnick
and
P.
Lugli
,
Phys. Rev. B
37
,
2578
(
1988
).
Google Scholar
 
11.
P.
Kinsler
,
P.
Harrison
, and
R. W.
Kelsall
,
Phys. Rev. B
58
,
4771
(
1998
).
Google Scholar
 
12.
J. H.
Smet
,
C. G.
Fonstad
, and
Q.
Hu
,
J. Appl. Phys.
79
,
9305
(
1996
).
Google Scholar
 
13.
C.
Sirtori
,
J.
Faist
,
F.
Capasso
,
D. L.
Sivco
,
A. L.
Hutchinson
, and
A. Y.
Cho
,
Appl. Phys. Lett.
69
,
2810
(
1996
).
Google Scholar
 
14.
P.
Harrison
and
R. W.
Kelsall
,
J. Appl. Phys.
81
,
7135
(
1997
).
Google Scholar
 
15.
P. Harrison, R. W. Kelsall, P. Kinsler, and K. Donovan, IEEE 6th International Conference on Terahertz Electronics Proceedings (1998), p. 74.
This content is only available via PDF.
© 1999 American Institute of Physics.
1999
American Institute of Physics
You do not currently have access to this content.