Modeling porosity of high surface area nanopowders of the gallium nitride GaN semiconductor

► GaN nanopowders with the BET surface areas from 6.3 to 222 m2 g−1 were prepared. ► Average crystallite sizes in the range 1.0-39.0 nm were calculated with Scherrer equation. ► Surface area of nanoparticles was modeled with close-packed equadimensional spheres. ► Selected model variants were successfully best-fitted with experimental data points. ► BET surface area of nanopowders corresponds with the surface area of the nanoparticles.