Photoluminescence study of InGaN films and InGaN/GaN quantum wells produced by molecular beam epitaxy

We have grown bulk InGaN films and InGaN/GaN multiple quantum well structures on A1₂0₃ substrates by electron cyclotron resonance assisted MBE method. Photoluminescence studies and measurements of far-IR reflection spectra have shown strongly inhomogeneoes spatial distribution of In in bulk InGaN films not only at high but at low In content as well. The inhomogeneity was absent in multiple quantum well structures with thin InGaN layers. Increase of the growth temperature has led to the inhomogeneous spatial distribution of In in the case of thin InGaN layers.