Synthesis, structures and temperature-dependent photoluminescence from ZnO nano/micro-rods on Zn foil

ZnO nano/micro-rods on Zn foil are fabricated through a simple, low-cost, catalyst- and seed-free solvothermal method by using Zn foil as the Zn2+ source and substrate in the sodium hydroxide solution. ZnO nano/micro-rods, which show good crystalline quality and grow along the c-axis, are distributed randomly on the Zn substrate and approximately perpendicular to the Zn substrate. Through analyzing the evolution of peak position and intensity of band gap emission with the temperature, two different non-radiative recombination processes are obtained. At low temperature the main non-radiative process is the thermal effect while at high temperature the main nonradiative process is the thermal escape from the structural defects assisted by LO phonon scattering. The understanding of the non-radiative recombination processes in ZnO nano/micro-rods on Zn foil might provide meaningful information for their potential application in the optoelectronic field.