Recent progress in basic ammonothermal GaN crystal growth

In this paper we would like to report the recent progress in basic ammonothermal GaN crystal growth. Growth on ammonothermal GaN seeds is presented. Structural properties of the seeds are shown and discussed. A new shape of seed crystals is proposed. It allows to eliminate the appearance of cracks in the growing GaN. The unwanted lateral growth is restricted and controlled. A higher growth rate, both in lateral and vertical directions, is obtained. Generally, the high structural quality of native seeds is maintained. In case of crystallization in lateral directions the structural quality of the seeds can even be improved. The influence of the crystallization run parameters, growth direction and configuration on the structural quality of the obtained GaN will be discussed.