Patent ID: 8480944

Claim:
A non-vacuum based process for making a quaternary chalcogenide wafer comprising: a. milling quaternary chalcogenide crystals to form milled particles with a particle size, d90 in the range of 0.1 micron to 10 microns, wherein the quaternary chalcogenide crystals are selected from the group consisting of Cu 2 ZnSnS 4 (CZTS); Cu 2 ZnSn(Sa,Se 1-a ) 4 , where 0≦a≦1 (CZTS/Se); and Cu 2 ZnSnSe 4 (CZTSe); b. compressing the milled particles at a temperature in the range of room temperature to 250° C. to form a quaternary chalcogenide wafer having a thickness in the range of 10 microns to 300 microns.