Growth of GaN crystals from molten solution with Ga free solvent using a temperature gradient

Seeded growth of GaN single crystals from solution at near atmospheric pressure

“…This technique requires pressures in the range of 150-400 MPa and growth rates are on the order of 1-2 mm/h. This work is a continuation of previous efforts [11,12] to develop a new technique, which meets critical requirements for the production of low defect density and low-cost GaN substrates. These requirements impose limitations on the direction of the development.…”

Optical properties of bulk GaN crystals grown from solution at moderate pressure and temperature

“…Presently, the performance of GaN-based devices is limited by the lack of high-quality GaN substrates with low dislocation density [5]. Several techniques have been used to grow bulk GaN, but each technique has its own limitations [6,7]. For example, it is possible to grow freestanding 2 in diameter GaN film on a sacrificial sapphire substrate, by hydride vapor phase epitaxy (HVPE) [6].…”

Bulk GaN crystal growth by the high-pressure ammonothermal method

“…Several groups have demonstrated GaN crystal growth by solution growth methods, using Ga [2,3], Na-Ga alloys [4,5], or inorganic compounds [6] as a flux, at pressures ranging from 1 to 20,000 atm. While impressive results have been achieved, including very low dislocation densities, the growth rates and scalability of these methods appear to be limited by a relatively low solubility for N and/or Ga in the flux.…”