Role of defect states in magnetic and electrical properties of ZnO nanowires

Abstract

The perfect crystalline nature along with a defect ridden surface controls the electrical and magnetic properties of ZnO nanowires. Herein, a soft chemical approach is presented to grow ZnO nanowires in powder as well as highly oriented nanowire film form. Photoluminescence measurements reveal high surface defects in as-grown nanowire and post growth annealing treatment in argon and oxygen atmosphere reduces intensity of defect emissions. Magnetic measurements illustrate the ferromagnetic nature of submicron sized zinc oxide (ZnO) nanorods arising due to singly charged oxygen vacancies. Nanowires show diamagnetic behavior when annealed at higher temperature in oxygen while argon annealing does not affect the magnetic behavior. In an analogous manner, we also investigated the effect of surface defects on electrical properties and correlated electrical conductivity with a responsible defect state.