Effects of aluminium doping on structural and photoluminescence properties of ZnO nanoparticles

Structural and optical properties of Al doped ZnO nanoparticles prepared by the thermal decomposition method are presented. X-ray diffraction studies confirmed the substitution of Al on Zn sites without changing the hexagonal structure of ZnO. Also, lattice parameters, the crystallite size and other physical parameters such as strain, stress and energy density were calculated from various modified forms of W–H equation and their variation with the doping of Al is discussed. A blue shift in the energy band gap attributed to increase in carrier concentration (Burstein Moss Effect) is observed by absorption spectra. Photoluminescence studies show a strong and dominant peak corresponding to the near band edge emission in ultraviolet range and a broad band in the range 420–520 nm corresponding to defects and oxygen vacancies. Phonon modes were studied by FTIR measurements. The tunability of the band gap of ZnO nanoparticles could eventually be useful for potential optoelectronic applications.