Bulk single-crystal growth of ternary AlxGa1−xN from solution in gallium under high pressure

We have successfully grown bulk, single crystals of AlxGa1−xN with the Al content x ranging from 0.5 to 0.9. Samples were grown from Ga melt under high nitrogen pressure (up to 10kbar) and at high temperature (up to 1800°C) using a gas pressure system. The homogeneity and Al content of the crystals were investigated by X-ray diffraction and laser ablation mass spectrometry. On the basis of the high-pressure experiments, the corresponding pressure–temperature (p–T) phase diagram of Al–Ga–N was derived. The bandgap of the material was determined by the femtosecond two-photon absorption autocorrelation method and is equal to 5.81±0.01eV for the Al0.86Ga0.14N crystals.