Regensburg 2004 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 50: Quantenpunkte und -dr
ähte: Optische Eigenschaften III

HL 50.5: Vortrag

Freitag, 12. März 2004, 12:00–12:15, H14

Influence of nitrogen containing barrier layers on the emission wavelength of InAs/GaAs quantum dots — •Oliver Schumann, Lutz Geelhaar, and Henning Riechert — Infineon Technologies AG, Corporate Research Photonics, 81730 München

We study the effect of varying the matrix material on the emission wavelength of InAs QDs. The addition of different combinations of nitrogen and indium into the matrix allows to tune the confining potential of the QDs and the local and global stress.

Samples have been grown by solid-source MBE assisted by a RF plasma source for nitrogen incorporation. They were examined by PL spectroscopy and TEM. We used a self-consistent Schroedinger-Poisson solver as a simple simulation tool for the changing confinement.

While growing the QDs on a GaAsN layer almost does not affect the PL wavelength, one can see a red shift of the emission wavelength greater than 100 nm after introducing nitrogen in the capping layer above the QDs. In this way an emission wavelength beyond 1.3 µm can easily be achieved. This tremendous red shift is mainly attributed to the change in the confining potential. By comparing QDs with quantum wells and samples with different concentrations of indium and/or nitrogen in the barrier layers, the role of stress with respect to the emission wavelength will also be discussed.