Structural properties of InGaN-based light-emitting diode epitaxial growth on Si (111) with AlN/InGaN buffer layer

This paper reports on structural characterization of InGaN-based light-emitting diode (LED) with AlN/InGaN buffer layer, AlN/GaN multi layer (ML) intermediate layer and AlGaN/GaN strain layer superlattices (SLS). The LED was epitaxially grown on Si (111) by metal organic chemical vapor deposition (MOCVD) that comprises of InGaN/InGaN multi quantum-wells (MQWs) active layer sandwiched between InGaN under-layer and over-layer. Phase analysis (PA) 2Theta-scan x-ray diffraction (XRD) proved the existence of single crystal GaN (0002) and (0004) at 34.5° and 73.2°, respectively. X-ray rocking curve (XRC) phi-scan showed six-fold symmetric diffraction peaks confirming the wurtzite GaN structures with consistent angular gaps of ~60°. The red shift of E₂ (high) GaN with respect to the standard value of strain-free bulk GaN denotes the presence of compressive strain in the epilayer. Surface morphology by atomic force microscope (AFM) shows a smooth surface with low RMS roughness value, thus proved a good quality of InGaN-based LED structure grown on Si.