Growth of M-Plane GaN(11-00): A Way to Evade Electrical Polarization in Nitrides
Abstract
We investigate the growth of M-plane GaN(100) on γ-LiAlO2(100) by molecular beam epitaxy. The crystal orientation and structural properties of buffer layers are examined by means of reflection high-energy electron diffraction, high-resolution transmission electron microscopy, X-ray diffraction, Raman scattering, and atomic force microscopy. The layers are shown to be single-phase GaN(1
00}<$>) within the measurements' sensitivity. In contrast to the ubiquitous C-plane GaN[0001] orientation, the M-plane of wurtzite nitrides is free of electrical polarization. This is experimentally verified for (Al,Ga)N/GaN heterostructures by continuous-wave and time-resolved luminescence.