A. Hoffmann, Institut für Festkörperphysik, TU Berlin
I
4
- donor bound exciton complex in ZnO
Reflection spectrosc py
Why VCSELs andwhy quantum dots (QDs)?
InGaN insertions inGaN as
dense arrays ofQDs
Surface lasing incavities withoutDBRs:
Narrow line, superlinear growth in intensity,
singlemode character,
high threshold excitationdensity
AlGaN/GaN DBRs and their impacton
the threshold excitationdensity
Room temperature photopumpedVCSELs
Far-field patterns of lasing and spontaneous
emission
Efficient InGaN/GaN/AlGaNLEDs
Resonant-cavity LEDs as prototypes of
current-injectionVCSELs
Conclusions
B. K. Meyer (start of common nitrid research)
3.46
3.47
3.48
GaN
(D
0
,X
B
)
(a)
Intensity (arb. units)
X
A
0
(D
0
,X
A
)
E
c
T=1.8K
3.48
3.49
3.50
3.51
Intensity (arb. units)
(D
0
,X
B
)
(b)
X
B
Energy (eV)
X
A
(n=2)
X
A
X
C
0.0
0.1
0.2
0.3
0.4
0.5
0.6
R
3440 3460 3480 3500
3440
3460
3480
3500
3520
3540
3560
A Plane sapphire
Si Substrate
Nelson et al.
SiC Substrate
C
A
B
C
B
A
SiC Substrate
ZnO substrate
dilatation
compression
T ~ 2K
GaN on sapphire
and others....
Energy (meV)
Energy of A line (meV)
B. Gil et al Phys. Rev. B (1996)
