Chemical beam epitaxy of GaInNAs/GaAs quantum wells and its optical absorption property

We examined quantum wells (QW) consisting of GaInNAs/GaAs grown by chemical beam epitaxy (CBE) using a radical nitrogen source, and the optical property of grown QWs was investigated by measuring of optical absorption spectra. It was found that the nitrogen composition was controlled linearly by the nitrogen flow and was increased by decreasing the growth rate. The nitrogen composition of GaInNAs was almost similar to GaNAs. The crystal quality was good for samples with the nitrogen composition of less than 0.02 and an indium content of 0.26. However, samples with larger nitrogen compositions showed degraded X-ray patterns and the reason is considered due to its miscibility gap. Step-like optical absorption spectra were observed and the absorption edge wavelength was elongated by increasing either nitrogen composition or well width. The conduction band offset energy of about 0.3-0.4 eV was estimated from the well width dependence of the absorption edge. (C) 1999 Elsevier Science B.V. All rights reserved.