PHOTOLUMINESCENCE OF RESIDUAL TRANSITION-METAL IMPURITIES IN GAN

A large number of epitaxial GaN samples as well as AIN ceramics have b een studied by photoluminescence (PL) and pi, excitation spectroscopy. In addition to the PL of residual iron, two new bands with zero-phono n-lines at 0.931 and 1.193 eV have been observed frequently in GaN. An analysis of the PL bands indicates that they arise from internal tran sitions within the 3d shell of residual vanadium and chromium impuriti es. The chromium PL has also been observed in polycrystalline AIN cera mics. (C) 1995 American Institute of Physics.