The calculated composition of heterostructure grown on Si for direct gap emission from at

We have calculated the composition of tensile strained Ge1−zCz on Ge1−x−y Six Sny heterostructures for which the indirect conduction band (L) lies above the zone centre ( Γ ) conduction band in the GeC layer in type I alignment. Linear interpolation of parameters indicates the possibility of achieving emission at 1.55 μm; however the direct gap shows a lower value when bowing parameters are considered.