Structural and optical characterization of high In content cubic InGaN on GaAs(001) substrates by RF‐MBE

High In content cubic InGaN films have been successfully grown on GaAs(001) substrates by rf-plasma assisted molecular beam epitaxy (RF-MBE). The X-ray diffraction analysis has confirmed the Ga content of the cubic InGaN films increases with increasing the group-III flux ratio (Ga/(Ga+In)). The maximum Ga content of the c-InGaN film is about 29% based on an analysis of the X-ray diffraction 2θ/ω scan. By 2θ/ω and ω X-ray reciprocal space mapping measurements, hexagonal-phase and twin-phase InGaN are found to be generated from c-InGaN{111} facets. By low temperature PL measurement, the c-In1–xGaxN peak shifts from 0.41 eV (x = 0) to 0.72 eV (x = 0.09) with increasing Ga content, showing that the bandgap of c-InGaN is ∼300meV smaller than that of h-InGaN with the same alloy composition. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)