GaN crystals growth in the Na-Li-Ca flux by liquid phase epitaxy (LPE) technique

•GaN crystal was grown by LPE technique in Na-Li-Ca flux solution at low temperature about 780 °C.•The smooth surface of as-grown GaN crystal was obtained because of lateral growth.•The dislocation density of as-grown GaN crystal could be directly reduced from 107 cm−2 to 103 cm−2.•The impurity defect concentration of as-grown GaN crystal could be decreased.