Design and characterization of strain-compensated GaInAs/GaAsSb type-II MQW structure with operation wavelength at ∼3 μm

GaInAs/GaAsSb type-II multiple quantum wells (MQWs) grown on InP substrates by molecular beam epitaxy (MBE) were investigated for potential use in p-i-n photodiodes operating in the mid-infrared spectral region. In these quantum well structures, electrons and holes are spatially separated. The resulting spatially indirect type-II detection occurs at longer wavelength than the spatially direct intraband recombination in either GaInAs or GaAsSb. A 4-band k . p Hamiltonian model was employed to calculate the detection wavelengths and wavefunction overlaps. A p-i-n structure with 100 pairs of Ga(0.66)In(034)As (similar to 7.0 nm)/GaAs(0.25)Sb(0.75) (similar to 5.0 nm) MQWs structure with operation wavelength of above 3.0 mu m was designed and grown by MBE. The compressively strained GaAsSb layers are strain-compensated by tensile strained GaInAs. Photo response of above 3 mu m was observed by room temperature responsivity measurements.