A team from Xiamen University designs artificial nanostructures that enhance deep ultraviolet light

In March, the Xiamen University research team innovatively designed an inverted pyramid/frustum artificial nanostructure that can greatly improve the extraction efficiency of deep ultraviolet light.

The researchers combined nano-imprint, dry etching technology and wet etching process to form (0001),(10-13) and (20-21) and other sets of finely controllable crystal faces on the (AlN) 8/(GaN) 2 active layer with emission wavelengths as short as 234 nm.

(a) Schematic flow chart for preparing nanopore arrays using nanoimprint technology;(a) -(c) Structural characterization of (AlN) 8/(GaN) 2 ultra-short period superlattice;(d)-(f) Nanopore holes and (g)-(h) Microscopic morphology of inverted pyramid/mesa nanopore arrays. These crystal surfaces can regulate the propagation and extraction mode of deep ultraviolet light waves in nanostructures, effectively breaking through the limitation of small cone angles of exiting light in traditional planar structures. After introducing an inverted pyramid/mesa structure with controllable crystal plane, TM and TE polarized light is enhanced by 5.6 times and 1.1 times respectively compared with planar structures, and the total luminescent intensity at the wavelength of 234 nm in deep ultraviolet is increased by nearly 2 times.

The launch of this research result will provide new ideas for improving the efficiency of deep ultraviolet short-wave light-emitting devices, and is expected to enable optoelectronic devices such as tiny size LEDs and deep ultraviolet detectors to have better optical properties.