Epitaxial semimetallic HfxZr1−xB2 templates for optoelectronic integration on silicon

High quality heteroepitaxial HfxZr1−xB2 (x=0–1) buffers were grown directly on Si(111). The compositional dependence of the film structure and ab initio elastic constants were used to show that hexagonal HfxZr1−xB2 possess tensile in-plane strain (0.5%) as grown. High quality HfB2 films were also grown on strain compensating ZrB2-buffered Si(111). Initial reflectivity measurements of thick ZrB2 films agree with first principles calculations which predict that the reflectivity of HfB2 increases by 20% relative to ZrB2 in the 2–8eV range. These tunable structural, thermoelastic, and optical properties suggest that HfxZr1−xB2 templates should be suitable for broad integration of III nitrides with Si.