Structural and optical properties of Cu2O nanoparticles formed on Al2O3 substrates using spin coating and thermal treatment

Cu2O nanoparticles were grown on Al2O3 substrates by spin coating and thermal treatment. X-ray diffraction patterns, scanning electron microscopy images, X-ray energy dispersive spectroscopy profiles, and high-resolution transmission electron microscopy images showed that Cu2O nanoparticles were formed on Al2O3 substrates. The photoluminescence (PL) peaks at 30 K were attributed to the excitonic peaks corresponding to interband transitions in the Cu2O nanoparticles, and the PL peak at 300 K was related to the optical phonons in the nanoparticles.