Strain distribution and band structure of mass-transported InAsP quantum wires buried in InGaAsP/InP

The mass-transport method can be used to form a high-quality InAsP quantum wire (QWR) array without any parasitic structures on an InGaAsP/InP V-grooved substrate. Although the emission peak wavelength and size of the mass-transported InAsP QWRs were proven to be controllable through the duration of the mass-transport process and the group V ambient pressure ratio, the shape of the emission spectrum was observed to be sensitive to the lattice mismatch of the barrier materials and the growth rate for burying the V-grooves. The reason for this sensitivity is not yet known. In this study, we have clarified the influence of strain on the band lineup in InAsP QWRs buried in InGaAsP pseudo-morphic to InP through calculations of strain distributions using a boundary element method under the assumption of isotropic elastic bodies. Although InAsP/InGaAsP interfaces have large conduction band offsets in bulk or quantum well (QWL) structures, the present work showed that the conduction band offset of this interface is small for the QWR structure. This is due to the larger volume reduction of InAsP for QWR heterostructures compared to those of QWLs.