Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density.ltoreq.100 cm.sup.-2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.
 This invention was made with United States Government support under contract number DE-FC26-08-NT01578 awarded by the Department of Energy (DOE) and contract number 70NANB4H3051 awarded by the National Institute of Standards and Technology (NIST). The United States Government has certain rights in the invention.