Annealing induced nanostructure and photoluminescence property evolution in solution-processed Mg-alloyed ZnO nanowires

Solution-processed Mg-alloyed ZnO nanowire arrays have been achieved recently without using high temperature annealing process. By introducing thermal annealing processes in oxygen-rich ambient condition, the UV near-band-edge (NBE) emission was surprisingly mitigated until disappeared with annealing temperature increasing from 400 to 900 °C. As the annealing temperature increased, intensity of UV peak decreased while intensity of visible peak (490–520 nm) increased. The structure evolution upon thermal annealing was revealed to be responsible for these abnormal photoluminescence property variations, where unusual (Zn,Mg)1.7SiO4 epitaxially evolved on ZnMgO nanowires surface and contributed to the quenching of UV NBE emission. The structure evolution induced UV-NBE quenching and nanoscale localized alloying in semiconductor ZnMgO nanowires could bring up opportunities in catalysis, optoelectronics, spintronics, and sensors.