Abstract: A method of forming an epitaxial article includes growing a crystal of elemental silicon having a minimum boron doping level of 3.2×1018/cm3 using Czochralski process parameters including a crystal growth velocity (pull speed) [V] which is less than (<) an average axial temperature gradient [G]. The crystal is cut into at least one elemental silicon substrate having a surface aligned to a <111> direction; wherein a ratio of vacancies/interstitials in the silicon substrate is less than (<) 1. At least one epitaxial buffer layer is grown on the surface of the silicon substrate, and at least one epitaxial Group IIIA-N layer is grown on the buffer layer(s).