We present intersubband absorption measurements performed on p-type quasistrain-compensated modulation-doped Si0.2Ge0.8/Si quantum wells grown on Si0.5Ge0.5 pseudosubstrates. Several intersubband absorption peaks are observed up to room temperature. A strong confinement shift of the resonance occuring between the ground and the first excited heavy hole states has been observed, with the absorption peak shifting from λ=5.3 μm to as short as 3.8 μm. Excellent overall agreement with a 6 band k⋅p calculation is obtained, proving the accuracy of recently predicted values of band offsets.

1.
J.
Faist
,
F.
Capasso
,
C.
Sirtori
,
D. L.
Sivco
,
A. L.
Hutchinson
, and
A. Y.
Cho
,
Science
264
,
553
(
1994
).
Google Scholar
 
2.
D.
Hofstetter
,
M.
Beck
,
J.
Faist
,
M.
Nägele
, and
M. W.
Sigrist
,
Opt. Lett.
26
,
887
(
2001
).
Google Scholar
 
3.
S.
Blaser
,
D.
Hofstetter
,
M.
Beck
, and
J.
Faist
,
Electron. Lett.
290
,
888
(
2001
).
Google Scholar
 
4.
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
 
5.
R. Q
Yang
,
C.
Lin
,
S. J.
Murry
,
S. S.
Pei
,
H. C.
Liu
,
M.
Buchanan
, and
E.
Dupont
,
Appl. Phys. Lett.
70
,
2013
(
1997
).
Google Scholar
 
6.
G.
Dehlinger
,
L.
Diehl
,
U.
Gennser
,
H.
Sigg
,
J.
Faist
,
K.
Ennslin
,
D.
Grützmacher
, and
E.
Müller
,
Science
290
,
2277
(
2000
).
Google Scholar
 
7.
L. Diehl, G. Dehlinger, H. Sigg, U. Gennser, D.Grützmacher, E. Müller, J. Faist, K. Ensslin, I. Sagnes, Y. Campidelli, O. Kermarrec, and D. Bensahel (unpublished).
8.
M. Y. A.
Yousif
,
O.
Nur
,
M.
Willander
,
C. J.
Patel
,
C.
Hernandez
,
Y.
Campidelli
,
D.
Bensahel
, and
R. N.
Kyutt
,
Solid-State Electron.
45
,
1869
(
2001
).
Google Scholar
 
9.
Note: for the sample with 35-Å-wide QWs, the doped regions have a lower doping concentration, but are slightly longer. The sheet carrier density in the QWs is, however, about the same for all the samples. Since the undoped layer grown before the Si cap was reduced by half, the use of a thin SiO2 layer was necessary to prevent any severe leakage current. Slightly higher voltages (+7/−2 V) were used to modulate the carrier concentration.
10.
T.
Fromherz
,
P.
Kruck
,
M.
Helm
,
G.
Bauer
,
J. F.
Nützel
, and
G.
Abstreiter
,
Appl. Phys. Lett.
68
,
3611
(
1996
).
Google Scholar
 
11.
T.
Fromherz
,
E.
Koppensteiner
,
M.
Helm
,
G.
Bauer
,
J. F.
Nützel
, and
G.
Abstreiter
,
Phys. Rev. B
50
,
15073
(
1994
).
Google Scholar
 
12.
C. G.
Van de Walle
and
R. M.
Martin
,
Phys. Rev. B
34
,
5621
(
1986
).
Google Scholar
 
13.
For a review on Fano-like interference effects in quantum wells, see J. Faist, C. Sirtori, F. Capasso, L. N. Pfeiffer, K. N. West, D. L. Sivco, and A. Y. Cho, in Intersubband Transitions in Quantum Wells: Physics and Device Applications I, edited by H. Liu and F. Capasso (Academic, New York, 2000), Vol. 66, Chap. 2, pp. 101–128.
14.
M.
Rieger
and
P.
Vogel
,
Phys. Rev. B
48
,
14276
(
1993
).
Google Scholar
 
15.
D. J.
Robbins
,
L. T.
Canham
,
S. J.
Barnett
,
A. D.
Pitt
, and
P.
Clacott
,
J. Appl. Phys.
71
,
1407
(
1992
).
Google Scholar
 
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.