PREPARATION OF GAN AND INN FOR BLUE-LIGHT-EMITTING SOURCES

Semiconductors based on nitrides of Al, Ga and In have gained consider able interest recently for the successful implementation of bright blu e and blue-green light emitting sources. Although most of the devices are based on hexagonal (wurtzite) GaN films, cubic (zinc blende) GaN f ilms are of great interest because of possible growth on GaAs. We have prepared GaN and InN from n-GaAs and InAs single crystal wafers by NN 3 treatment at 700 degrees C. X-ray diffraction measurements showed bo th cubic and hexagonal phases of GaN and InN. N-2 plasma treatment of liquid phase epitaxy grown InGaAs at 900 degrees C resulted in growth of separate phases of only cubic GaN and InN. Optical absorption studi es on GaN showed a direct band-gap of 3.46 eV. Photoluminescence measu rements on GaN showed a defect-related emission band at 2.75 eV.