Formation of nanoporous germanium layers wirh various morphology by ion implantation for anodes of lithium-ion batteries

The morphology of the surface of nanoporous Ge (PGe) layers formed during low-energy high-dose implantation with transition metal ions (Cr⁺ 52, Mn⁺ 55, Fe⁺ 56, Co⁺ 59, Ni⁺ 59, Co⁺ 63) depending on their mass was studied by high-resolution scanning electron microscopy. For this aim, ion implantation of monocrystal c-Ge plates was carried out using same conditions at an energy of 40 keV and a dose of 5.0×10¹⁶ ion/cm². For comparative experiments on changing the morphology of PGe an irradiation of c-Ge with heavier Ag⁺ 108 and Sb⁺ 122 ions at 30 keV was performed. It was shown that the morphology of the PGe layers changes its structure from labyrinth, hole, three dimensional reticular to spongy-like with increasing mass of the irradiated ion. (authors)