Investigation of the Structural and Optical Properties of Compositionally V‐Graded Strained InxGa1–xN Layers

Abstract

Compositionally graded InxGa1–xN‐based materials have been receiving more attention recently due to both their novel structure and intrinsic properties. However, high‐quality material with a well‐controlled and optimized grade to high In composition remains challenging to grow. Herein, the growth and characterization of continuous 2D films of compositionally graded InxGa1–xN are investigated using molecular beam epitaxy (MBE) on (0001) GaN templates at 575 °C. Each film is formed by compositionally grading the growth from GaN to InxGa1–xN and back to GaN, symmetrically, such that the bandgap and the composition of Ga follow a V‐shaped pattern. Here x has been chosen to be ≈0.20 and 0.22. These compositions are confirmed through high‐resolution X‐ray diffraction simulations. Furthermore, asymmetric reciprocal space mapping reveals complete coherence with the GaN substrate. Finally, photoluminescence is measured at low temperature to demonstrate the luminescent properties of the films.