Density functional theory study of quaternary InPBiN alloys lattice matched to InP substrate: Structural, electronic and optical properties

Abstract

In this work, we would like to determine the physical properties of the quaternary InBixP1−x-yNy alloys lattice matched to InP substrate. Indeed, the matched InBixP1−x-yNy /InP structure can be a good proposal for devices applications without defects generation at the interface and with unstrained InBixP1−x-yNy properties. We have performed this calculation based on density functional theory (DFT) and by using the full-potential linearized augmented plane (FP-LAPW) implemented in Win2k code. This study concerns the electronic, and optical properties, including band structure, density of states, dielectric function, refractive index and energy loss function calculation for the ratio x/y = 0.97 ensuring perfect match between InBixP1−x-yNy and InP substrate. It is found that the incorporation of Bi into InP matrix leads to a significant decrease of the energy gap of about 53/%Bi. The co-alloying of InBixP1−x material by nitrogen (N) is perfect solution to accommodate the quaternary InP1−x-yNxBiy alloy to the InP substrate. Furthermore, the increase of N and Bi content leads to a strong shrinkage of band gap energy. Thus, the calculated data of InP1−x-yNxBiy band gap indicates that it is possible to generate the two emissions at 1.077 eV (1.3 µm) and 0.833 eV (1.5 µm), having a vital importance in telecommunications by optical fibers. It is worth pointed that these emissions are characterized by higher optical efficiency and less energy loss that opening the way to use this structure in several electronic applications.