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
Shift of the absorption edge in SnO
2
films with high
concentrations of nitrogen grown by CVD
The optical and electrical properties of n-type SnO
2
films with high
concentrations of nitrogen (SnO
2
:N) grown by chemical vapor deposition are
studied. The carrier concentration increases from 4.1
×
1018 to
3.9
×
1019 cm−3 and the absorption edge shifts from 4.26 to 4.08 eV with
increasing NH
3
flow rate. Typical Urbach tails were observed from the
absorption spectra and the Urbach energy increases from 0.321 to 0.526 eV
with increasing NH
3
flow rate. An “effective” absorption edge of about 4.61 eV
was obtained for all
investigated samples from fitting the extrapolations of the
Urbach tails. Burstein-Moss effect, electron-impurity, and electron-electron
interactions are shown to play a minor role for the shift of the absorption
edges in SnO
2
:N thin films.
Jie Jiang, Yinmei Lu, Bruno K. Meyer, Detlev M. Hofmann and Martin Eickhoff, J. Appl. Phys. 119, 245703 (2016)
