Characterization of $M$-plane InGaN/GaN Quantum Wells Grown on Misoriented $\gamma $-LiAlO$_{2}$ by Plasma-Assisted Molecular Beam Epitaxy

We have grown a series of InGaN/GaN quantum wells on misoriented LiAlO$_{2}$ (LAO) substrate with different growth parameters by plasma-assisted molecular beam epitaxy (PAMBE). The sample structure consists of \textbf{\textit{M}}-plane InGaN/GaN quantum wells(25nm GaN barrier/5nm InGaN well) with a $\sim$ 225nm GaN buffer layer between the quantum wells and LAO substrate. The mis-cut angle of LAO substrate was tilted 11$^{\circ}$ off [011] direction to match the atoms of GaN lattice. From the X-ray diffraction (XRD) measurement, we found two peaks of 34.6$^{\circ}$ and 32.2$^{\circ}$, indicating the LAO(100) substrate and [1\underline {1}00] oriented (\textbf{\textit{M}}-plane) for the GaN thin films, respectively. The surface morphology, optical property and microstructure of the samples were investigated by scanning electron microscope (SEM), photoluminescence (PL) and transmission electron microscope (TEM) measurements, as well.