Doping of nanocrystalline silicon with sulfur by gas-phase diffusion

•Sulfur-doped nanosilicon particles were synthesized by gas-phase diffusion.•Maximum dopant concentration of 0.5 % mol. was achieved at 700 °C.•Crystalline silicon rods form at 900 °C, up to 300 μm long.•Synthesized at 900 °C sample has a direct bandgap transitions with energy of 1.09 and 1.69 eV.•Synthesized at 900 °C sample was found to show high conductivity and stability.