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Optical properties of GaInNAs/GaAs quantum wells: character of optical transitions and carrier localization effect
|R. Kudrawiec 1, J. Misiewicz 1, M. Fischer 2, A. Forchel 2
1. Wroclaw University of Technology, Institute of Physics, Wybrzeże Wyspiańskiego 27, Wrocław 50-370, Poland
GaInNAs/GaAs quantum wells (QWs) were grown by molecular beam epitaxy (MBE) on GaAs substrate. Such structures are very promising materials for optoelectronic devices operated at 1.3 and 1.55 μm, however their optical properties are still controversial and not fully understood. In this work, optical properties of the compounds and QWs have been studied by photoluminescence (PL) and photoreflectance (PR) spectroscopies. The character of optical transitions has been investigated at 10 and 300 K. Many interesting features have been found for these structures. We have observed both well known (like e.g. carrier localisation effect, Stokes shift, annealing induced blue-shift detected in PL) and not reported so far experimental facts (a decrease of the modulation efficiency with a decrease of temperature, an increase of PR transition broadening with a decrease of temperature, annealing induced blue-shift detected in PR). In this work we have focused on the carrier localisation effect and their influence on the character of optical transitions. The strong localisation effect can be attributed to alloy fluctuation and different nitrogen nearest-neighbour environment. It has been observed that a rapid thermal annealing (RTA) essentially reduces the carrier localisation. In addition, the RTA induces a blue-shift of energy band gap. The nature of the shift and emission bands are discussed in this work.
Presentation: poster at E-MRS Fall Meeting 2003, Symposium C, by R. Kudrawiec
See On-line Journal of E-MRS Fall Meeting 2003
Submitted: 2003-06-16 16:57 Revised: 2009-06-08 12:55