论文信息 - Optimisation of MBE growth conditions for InAs quantum dots on (001) GaAs for 1.3 μm luminescence

Optimisation of MBE growth conditions for InAs quantum dots on (001) GaAs for 1.3 μm luminescence

We present a study of the optimised growth conditions for InAs quantum dots (QDs) grown on GaAs substrates by solid source molecular beam epitaxy (SSMBE). Growth conditions for best luminescence intensity and linewidth were found within narrow windows of substrate temperature (500-520 C) and nominal InAs layer thickness (3.3-3.7 monolayers). The emission wavelength of such InAs QDs capped by GaAs was around 1.24 μm. However, this is red-shifted to 1.3 μm or more by capping the InAs QDs with a thin layer of In x Ga 1 x As. The results show that both In content and thickness of the capping layer can be used to tune the emission wavelength. Atomic force microscopy images show that the surface recovers to two-dimensional when depositing In 0.2 Ga 0.8 As while remaining three-dimensional when depositing In 0.4 Ga 0.6 As.

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