The Self-catalytic and Catalyst Assisted CVD Growth of High Optical Quality AlGaN Nanowires

The wide and direct band gap AlGaN nanowires (NWs) are synthesized using chemical vapor deposition technique at a growth temperature of 915 degrees C using self catalytic vapor-solid (VS) as well as catalyst assisted vapor-liquid-solid (VLS) mechanism. Vibrational studies using Raman spectroscopy confirmed the formation of wurtzite phase of AlGaN and show the two-mode phonon behavior of the random alloy formation. Room temperature photoluminescence (PL) studies of AlGaN grown via self catalytic approach further supports the formation of AlGaN alloy with free exciton emission energy higher than the reported band gap for GaN. Relatively defect free PL emission achieved for the AlGaN NWs grown via catalyst assisted VLS mechanism by modulating the Au nanoparticles distribution on the Si(100) substrate.