Zero-Net-Strained (ZNS) InGaAsP/InGaAsP/InP Multi Quantum Wells (MQW) structures grown by Low Pressure Metalorganic Vapor Phase Epitaxy for 1.55mum laser applications were investigated using atomic force microscopy, photoluminescence spectroscopy and X-ray diffraction. The morphology exhibits a strong anisotropic and modulated behavior. The photoluminescence spectrum shows a broad emission band below the fundamental quantum well transition. The results indicate a strong influence of the growth rate, growth temperature and barrier composition on the surface morphology, and on the optical and structural properties of the ZNS structures. Ridge wave-guide ZNS-MQW laser structures grown at optimized conditions exhibited excellent electro-optic characteristics with low threshold current and high efficiency.

We have investigated the optical and the structural properties of strained In1-xGaxAsyP1-y/InP and strain compensated In1-xGaxAsyP1-y/In1-zGazAsqP1-q/InP multi-quantum well heterostructures grown by low-pressure metalorganic vapor phase epitaxy at different growth conditions. Our results indicate an increase of the compositional fluctuation of quaternary materials as the alloy composition moves from the outer spinodal isotherm into the miscibility gap region. In1-xGaxAsyP1-y layers grown at high tensile strained values exhibit a three-dimensional-like growth mode. Strain compensated structures revealed the presence of a broad photoluminescence emission band below the fundamental quantum well transition, well defined elongated features along the [011] direction and interface undulations. All these effects were found to be strongly dependent on the growth temperature and the number of wells.