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 (Begi n der gemeinsamen Nitridforschung )
Undoped ZnO
Donor bind ng en rgi
D
0
X - TES(2p) spacing:
Effective mass donors:
E
D
= (E
2P
– E
1S
) + 12.61meV
Haynes rule:
Linear increase of E
D
with E
loc
E
loc
= a + b
E
D
Exciton Typ Impurity Energy
(eV)
E
loc
(meV)
E
D
(meV)
I
4
D
0
X
H
3.3628
13.1
46.1
I
6
D
0
X
Al
3.3608
15.1
51.5
I
8
D
0
X
Ga
3.3598
16.1
54.6
I
9
D
0
X
In
3.3567
19.2
63.2
