Metalorganic Molecular Beam Epitaxy of InGaN Layers and Their Optical Properties

We report on the growth of InGaN/GaN heterostructures on the nitridatedα-A2O3 substrate using metalorganic molecular beam epitaxy (MOMBE) system equipped with an N2 rf-plasma cell. An In incorporation of 41% was achieved without InN phase separation in the InGaN film. The InGaN films showed photoluminescence (PL) spectra corresponding to blue, green, and red colors depending on the In composition. The XRD and PL measurements showed that the red emission from InGaN was originated from the phase-separated InN in the InGaN film.