Effect of AlAs mole fraction on the integrated luminescence intensity of GaAs/AlxGa1-xAs quantum well heterostructures

摘要

The photoluminescent properties of GaAs/Al$-x$/Ga$-1 $MIN x$/As multiple quantum well structures grown on (100) GaAs substrates by molecular beam epitaxy have been investigated as a function of the AlAs mole fraction. It is found that as the AlAs mole fraction in the Al$-x$/Ga$-1 $MIN x$/As barriers is increased, the corresponding photoluminescent peak intensity of the quantum well structures increases and reaches a maximum at an AlAs mole fraction of about 45%. Further increases in the Al content of the barriers beyond 45% results into a decrease in the luminescence efficiency. At the maximum intensity, the peak luminescence from the quantum well structures is enhanced by about two orders of magnitude (at room temperature) when compared to the luminescence from such structures with an AlAs mole fraction of 20% in the barriers.