Patent ID: 8071466

Claim:
A method for producing a ZnS structure having at least 95% wurtzite structure by volume and being either a single crystal or a multi-grain ZnS crystal with an average grain size of at least 1 mm by a physical vapor transport method, comprising the steps of: disposing a ZnS source in a high purity crucible located at one end of a growth furnace enclosure; heating said ZnS source material to a temperature in the range of 1350Â° C. to 1650Â° C. generating a vapor-phase of said ZnS source; providing a carrier gas selected from the group consisting of Ar, N 2 , He and mixtures thereof at a total gas pressure within the growth furnace enclosure in the range of 10 torr to 1,500 torr; and depositing said ZnS structure at a second end of said growth furnace enclosure an average crystal growth rate in the range of 0.2 mm-4.0 mm/hr.