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 Er³⁺ 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. This study points to the effective methods to enhance 1540 nm emission, demonstrating that ZnO NRAs with Ag islands have a promising potential for the application in optical communications.