Progress of Na-Flux Method for Large-Size GaN Single Crystal Growth

Gallium nitride (GaN) is an ideal semiconductor material for the development of microelectronic and optoelectronic devices. Homo-epitaxial growth on high-quality GaN single crystal substrates is the fundamental way to achieve high performance of GaN-based devices, and the Na-flux method is an effective way to grow large-size GaN single crystals by liquid phase epitaxy (LPE). In this paper, the growth of large-size GaN single crystals by the Na-flux method is systematically reviewed, and the main achievements are summarized. The development trend and main challenges of the Na-flux method for the growth of GaN single crystals are examined.