Annealing effects on the field emission properties of AlN nanorods

The effects of thermal annealing on the field emission properties of AlN nanorods treated in different ways were investigated. A strong correlation was observed between the nitrogen vacancy concentration and the field emission properties of the samples. The sample annealed in ammonia had a higher emission current than the as-grown and vacuum-annealed samples. Raman and cathodoluminescence analyses revealed that the sample treated with ammonia had the smallest nitrogen vacancy density and the lowest work function, leading to the best field emission properties. These results indicate that post-treatment is an effective way to improve the field emission properties of AlN nanostructures.