LATTICE AND ELECTRONIC-STRUCTURE PROPERTIES OF (ALN)(X)(SIC)(1-X) SEMICONDUCTING ALLOY

The band-gap bowing in zincblende (AlN)(z)(SiC)(1-x) is studied by mea ns of the empirical pseudopotential method (EPM) coupled with the virt ual crystal approximation (VCA) which takes into account the compositi onal disorder as an effective potential. The results obtained within t he VCA show that the bowing parameter is not so important, whereas the adding of the compositional disorder to the VCA clearly shows that th e bowing is rather important in such material. Calculations of the cha rge densities have shown how the bands behave as the composition chang es and this is highly linked to the ionicity character. The variations of the bulk modulus, the force constants and the elastic constants wi th the alloy concentration are also established. The computational res ults agree well with available theoretical and experimental data.