Large area group III nitride crystals and substrates, methods of making, and methods of use

A free-standing group III metal nitride substrate comprising at least two crystals, each of the at least two crystals comprising:

• a group III metal selected from gallium, aluminum, and indium, or combinations thereof, and nitrogen, wherein:
• each of the at least two crystals having a wurtzite crystal structure comprises a first surface having a maximum dimension greater than 10 millimeters in a first direction and a maximum dimension greater than 4 millimeters in a second direction orthogonal to the first direction, an average concentration of threading dislocations between 102 cm−2 and 1×106 cm−2, an average concentration of stacking faults below 103 cm−1, a symmetric x-ray rocking curve full width at half maximum less than 200 arcsec,
• the magnitudes of a crystallographic miscut of the first surfaces of each of the at least two crystals are equal, to within 0.5 degree,
• the directions of crystallographic miscuts of the first surfaces of each of the at least two crystals are equal, to within 10 degrees,
• each of the at least two crystals is bonded to a matrix member comprising polycrystalline GaN that is textured in a c-direction, and
• a polar misorientation angle γ between a first surface of a first crystal of the at least two crystals and a first surface of a second crystal of the at least two crystals is greater than about 0.005 degrees and less than about 0.2 degrees and misorientation angles α and β are greater than about 0.01 degrees and less than about 1 degree.