Molecular beam epitaxy of InAlN alloys in the whole compositional range

The fabrication of high-quality InxAl1-xN alloys over the whole composition is very challenging. Controlling the In/(In + Al) beam flux ratio and the growth temperature, this paper reports the fabrication of single crystalline InxAl1-xN alloys over the whole In composition by radio-frequency plasma-assisted molecular beam epitaxy. A comprehensive systematic study on the structural and vibrational properties of the InxAl1-xN alloys for the whole In composition has been carried out experimentally by Raman spectroscopy and theoretically by the forced vibrational method. The InxAl1-xN alloys show broad Raman peaks in the intermediate range of In composition. The appearance of Raman inactive B-1 (High) mode has been confirmed by the experimental and theoretical results. The B-1 (High) and A(1) (LO) modes show one-mode behavior, whereas the E-2 (High) mode shows the two-mode behavior in the whole In composition range. The observed Raman modes from the grown InxAl1-xN alloys well match with the calculated phonon modes of the InxAl1-xN alloys. These results provide an in-depth understanding of the growth of whole compositional InxAl1-xN alloys and the fabrication of optoelectronic devices using these promising materials. (c) 2020 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).