Formation of hexagonal-wurtzite germanium by pulsed laser ablation

A stable phase of relatively large hexagonal-wurtzite germanium (lonsdaleite) crystals (up to 10 μm) was formed when germanium was directly deposited at low pressure using pulsed ultraviolet laser ablation. Films were grown on various substrates at room temperature from a single crystal, cubic germanium target. Crystallites of the hexagonal-wurtzite phase of germanium were clearly identified using selected area electron diffraction. Further characterizations of the films were made using X-ray diffraction and confocal scanning micro-Raman spectroscopy.