The investigation of $Al0.29Ga0.71N/GaN/AlN$ and AlN/GaN/AlN thin films grown on Si (111) by RF plasma-assisted MBE

Recently, gallium nitride (GaN) and its related compounds involving Al and In have attracted much attention because of their potential to be used as high-efficiency UV light emitting devices, and as high frequency and high power electronic devices. Consequently, the growth and physics of GaN-based materials have attracted remarkable scientific attention. In this work, the growth and characterization of epitaxial $Al0.29Ga0.71N$ and AlN layers grown on Si (111) by RF-plasma assisted molecular beam epitaxy (MBE) are described. The Al mole fraction was derived from the HR-XRD symmetric rocking curve (RC) ω/2θ scans of (0002) plane as $x = 0.29$⁠. For AlN/GaN/AlN sample, the maximum Raman intensity at 521.53 cm⁻¹ is attributed to crystalline silicon. It was found that the allowed Raman optical phonon mode of GaN, the E₁ (high) is clearly visible, which is located at 570.74 cm⁻¹. Photoluminscence (PL) spectrums of both samples have shown sharp and intense band edge emission of GaN without the existence of yellow emission band, showing good crystal quality of the samples have been successfully grown on Si substrate.