Synthesis of Bulk GaN Single Crystals Using Na-Ca Flux

The influences of supersaturation on LPE growth of GaN single crystals using the Na flux method

“…5, though the surface, which had grown in the late term of the growth period, was transparent. We reported that the coloring of GaN single crystals grown in the Na flux system was probably due to the nitrogen vacancies in the crystal [13,20,21]. The nitrogen concentration in the Na-Ga melt at 800 1C at the beginning of LPE growth is estimated at about 0.11 at% (the N/Ga ratio in the solution is 4.6 Â 10 À3 ), which is the minimum value to grow GaN at 800 1C [19].…”

GaN single crystals grown under moderate nitrogen pressure by a new flux: Ca3N2

“…Using NaN 3 as flux and metallic Ga as raw material, Yamane et al [10] reported transparent GaN single crystals grown at 750 1C under 5 MPa nitrogen pressure. In addition, it has been demonstrated that metallic Na or mixtures of Na and Ca can serve as flux for GaN crystals growth in a similar approach [11,12] Na flux methods. It was found that the pressure threshold was decreased and the quality of GaN crystals was improved by the addition of metallic Ca to Na flux [11,12].…”

“…In addition, it has been demonstrated that metallic Na or mixtures of Na and Ca can serve as flux for GaN crystals growth in a similar approach [11,12] Na flux methods. It was found that the pressure threshold was decreased and the quality of GaN crystals was improved by the addition of metallic Ca to Na flux [11,12]. But, only metallic Ca failed to grow GaN single crystals as flux [11].…”

Crystal growth of GaN by ammonothermal method

“…Different process routes based on sublimation/ recondensation, evaporation/reaction and solution/reaction mechanisms are currently under rapid development [7][8][9][10][11]. Among such methods, ammonothermal method utilizes a solution/reaction mechanism and allows GaN to be obtained with high purity and crystallinity.…”