InGaAs/InP and InAsP/InP quantum wells on GaAs (100) with graded In/sub x/Ga/sub 1-x/As or In/sub 1-y/Ga/sub y/P buffer layers grown by gas-source molecular beam epitaxy

We compare the use of compositionally linearly graded In/sub x/Ga/sub 1-x/As and In/sub 1-y/Ga/sub y/P buffer layers for growing InP-based heterostructures on GaAs substrates. For both cases, a two-dimensional layer-by-layer growth mode is maintained. These buffers are effective in relaxing the top active layers almost completely and isotropically. Optical properties of In/sub 0.53/Ga/sub 0.47/As/InP and InAs/sub z/P/sub 1-zInP quantum wells are comparable to similar structures grown on InP substrates. The advantages of In/sub y/Ga/sub 1-y/P over In/sub x/Ga/sub 1-x/As buffer layers are discussed. The quantum-confined Stark effect is observed near 1.3 /spl mu/m for InAs/sub 0.4/P/sub 0.6InP multiple quantum wells grown on GaAs.<
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