Effects of annealing on arrays of Ge nanocolumns formed by glancing angle deposition

► Free-standing, polycrystalline Ge nanocolumn arrays are obtained by controlled thermal annealing. ► Annealing induces considerable morphology coarsening and re-crystallization at ∼500 °C. ► Nanostructures deposited on pre-patterned substrates retained their shape even at ∼700 °C. ► TEM investigation revealed nano-crystalline domains of the order of 5-30 nm within annealed nanostructures.