Effects of Covering Layer on Extending the Emission Wavelenghs of InAs Quantum Dots

A new method to tune the emission wavelength of InAs self-assembled quantum dots(QDs) was proposed.The emission wavelength of the InAs QDs grown by molecular beam epitaxy(MBE) was extended to 1.3 μm～1.5 μm range by introducing a covering layer of short period GaAs/InAs superlattice on the QDs.The influence of the different periods of the superlattice on the erystal structure and optical property was investigated.An abnormal phenomenon was found that the photoluminescence intensity was increased with increasing the measuring temperatures.This phenomenon was attributed to the mechanism of carrier transferring processes between QDs.