Structural and antireflective characteristics of catalyst-free GaN nanostructures on GaN/sapphire template for solar cell applications

摘要

We report the structural and antireflective characteristics of catalyst-free GaN nanostructures on GaN/sapphire template for solar cell applications. The formation of GaN nanostructure depends on the growth temperature. At 530℃, the nucleation of the initial seed due to the enhanced strain leads to the hexagonal closely packed nanorods. As the growth temperature decreases, the depression of atomic Ga transport changes the films into nanocolumns, and then the nanorods. The catalyst-free GaN nanorods have wurtzite structure and good single crystalline quality. The GaN nanorods exhibit a remarkably low reflectance over a wide-angle broadband spectrum, enhancing the antireflective property of GaN surface.