ZnO nanorod heterojunctions and LEDs

Zinc oxide (ZnO) nanorods are of great interest due to their potential use in optoelectronic devices. Hydrothermal synthesis and electrodeposition are two very promising techniques for ZnO growth as they are simple and inexpensive and also involve low fabrication temperature, favoring the use of large area and/or flexible substrates. In this work, we investigated the influence of the seed layer on the morphology and optical properties of ZnO nanorods, as well as the influence of post-fabrication treatments, such as annealing under different conditions. To further demonstrate the potential use of ZnO nanorods in optoelectronic devices, light emitting diodes (LEDs) were also studied in this paper. We have focused on heterojunction devices with ZnO as an n-type layer, since heterojunction ZnO LEDs typically exhibit better performance compared to homojunctions. We have investigated devices using GaN and NiO as a p-type material, and in addition hybrid organic/inorganic devices were also prepared.