Electronic structures of well-aligned Er-doped ZnO nanorod arrays.

Electronic structures of well-aligned Er-doped ZnO (ZnO:Er) nanorod arrays (NRAs) synthesized by a solution-based hydrothermal process were characterized by high-resolution transmission electron microscopy (HRTEM) and X-ray absorption fine structure (XAFS). HRTEM and angular dependent X-ray absorption near-edge structure analysis at O K and Zn L3 edges indicates that the spontaneous polarization is along the [0001] direction. The analysis of Er L3-edge XAFS demonstrates that the local structure around Er in the ZnO:Er NRAs was transformed from O(h) to C(4v), after annealing.

Er-doped ZnO nanorod arrays with enhanced 1540 nm emission by employing Ag island films and high-temperature annealing.

Single-crystalline Er-doped ZnO nanorod arrays (NRAs) on Ag island films with appropriate annealing show a promising enhancement of 1540 nm emission for optical communication. The enhanced 1540 nm emission of Er-doped ZnO NRAs is attributed to the enhancement of the deep level emission of ZnO host. In an effort to enhance deep level emission to pump Er(3+) emission at 1540 nm in the Er-doped ZnO NRAs, surface plasmon coupling and increase in deep level states were carried out via Ag island films and high-temperature annealing.