Journal of Crystal Growth, Vol.521, 30-33, 2019
GaN crystals growth in the Na-Li-Ca flux by liquid phase epitaxy (LPE) technique
10 x 10 mm(2) area GaN crystals were successfully grown on HVPE-GaN seed by LPE technique in Na-Li-Ca flux. Many growth hillocks with hexagonal shape were formed on the surface of crystal when the growth time was 150 h. Due to the lateral growth, the smooth Ga-face could be obtained after growth 300 h. The dislocation density could be decrease from 10(7)cm(-2) to 10(3)cm(-2) with increasing GaN crystal growth thickness. The reduction mechanism of dislocation was discussed. The PL spectra showed that the relative intensity of the yellow band luminescence peak of GaN crystals was obviously reduced comparing with HVPE-GaN seed, which indicated that the impurity defects in the crystal could be effectively suppressed.
Keywords:Single crystal growth;Seed crystals;Liquid phase epitaxy;Nitrides;Semiconducting III-V materials