Evolution of surface morphology and optical characteristics of 1.3-μm In_(0.5)Ga_(0.5)As/GaAs quantum dots (QDs)grown by molecular beam epitaxy(MBE)are investigated by atomic force microscopy(AFM)and photoluminescence(PL).After deposition of 16 monolayers(ML)of In_(0.5)Ga_(0.5)As,QDs are formed and elongated along the [110] direction when using sub-ML depositions,while large size InGaAs QDs with better uniformity are formed when using ML or super-ML depositions.It is also found that the larger size QDs show enhanced PL efficiency without optical nonlinearity,which is in contrast to the elongated QDs.
The GaAs based InGaAs metamorphic structures and their growth by molecular beam epitaxy (MBE) are investigated. The controlling of the source temperature is improved to realize the linearly graded InGaAs metamorphic structure precisely. The threading dislocations are reduced. We also optimize the growth and annealing parameters of the InGaAs quantum well (QW). The 1.3-μm GaAs based metamorphic InGaAs QW is completed. A 1.3-μm GaAs based metamorphic laser is reported.
