InGaAs/GaAs应变层量子阱的光学性质

Optical Properties of InGaAs/GaAs Strained Layer Quantum Wells

当由两种晶格失配的材料组成量子阱时,只要每层的厚度小于临界值,则两种材料会通过应变而使界面处不产生失配位错,可获高质量的晶体材料。这谓之应变层超晶格结构。

The intensity oscillation of RHEED was usad to determine the optimum growth temperature of InGaAs/GaAs strained layers. The high quality SLS was characterized by X-ray rocking curves, PL spectra and TEM micrographs. The PL studies of strained quantum wells at 77K and at high pressures up to 50kbar were performed. The pressure coefficients of the valley of QW's are presented for the first time. The crossover between the energy level in the well and the X valley in the GaAs barrier was observed. The ratio of CB band offset to VB at heterojunction was determined and magneto--optical absorption spectra were measured under a steady magnetic field of up to 6 T. The binding energy of the heavy hole exciton was obtained and the reduced mass of the exciton was also determined from this experiment.