Tailoring of ZnO with selected group-II elements for LED materials

The semiconductor ZnO is a promising candidate for its applications in light-emitting diodes. In this study ZnO nanostructures tailored with selected group-II elements were synthesized using sol–gel-based fuel-agent-assistive chemical technique. Structural studies from X-ray diffraction analysis revealed the presence of wurtzite hexagonal crystal structure in all compositions confirming the stability of the Mg-doped structure while indicating presence of some traces of un-reacted and oxides of Sr and Ba in other compositions. Lattice parameters, crystallite size, lattice strain, density, and cell volume were extracted from X-ray diffraction data. Morphology and elemental composition analysis showed exact correlation with structural arrangements. The size of particles was also observed with dynamic light-scattering measurements. Absorbance and electrical transport studies were performed using UV–Vis spectrophotometry and four-probe measurements, respectively; the former was used to estimate the band gap of nanostructures. Energy-dispersive X-ray analysis was employed for confirming the substitution of Mg, Sr, and Ba atoms at Zn and O sites. Band gap values show strong dependence upon the tailored ZnO compositions.