A method of growing bulk single crystals of an AlN on a single crystal seed is provided, wherein an AlN source material is placed within a crucible chamber in spacial relationship to a seed fused to the cap of the crucible. The crucible is heated in a manner sufficient to establish a temperature gradient between the source material and the seed with the seed at a higher temperature than the source material such that the outer layer of the seed is evaporated, thereby cleaning the seed of contaminants and removing any damage to the seed incurred during seed preparation. Thereafter, the temperature gradient between the source material and the seed is inverted so that the source material is sublimed and deposited on the seed, thereby growing a bulk single crystal of AlN.