Comprehensive study of the nanoporous si layer influence on atomic and electron structure and optical properties of A$^{\mathrm{III}}$N/por-Si heterostructures grown by plasma assisted molecular beam epitaxy

The influence of using a buffer sublayer of nanoporous por-Si on the morphological, physical, and structural properties of nanocolumnar In$_x$Ga$_{1-x}$N structures fabricated by plasma-activated molecular-beam epitaxy on single-crystal Si(111) substrates is shown. Using a set of structural-spectroscopic analytical methods, the electronic structure of the grown heterostructures, morphology, and optical properties are investigated, and the interrelations between them are established. It is shown that the use of a por-Si sublayer makes it possible to attain a more uniform distribution of diameters of In$_x$Ga$_{1-x}$N nanocolumns and to increase the photoluminescence intensity of the latter.