The DBRs consist of alternating dielectric layers, commonly serving as reflectors and dielectric mirrors, and their multilayered composition alternates between high and low refractive indices, resulting in customizable reflection spectra.

The DBR structures exhibit a distinct blue hue and use transparent conductive oxides (TCOs) derived from thin-film aluminum-doped zinc oxide (AZO) and indium tin oxide (ITO). This choice of materials reportedly enhances light scattering. The connection between TCOs and the DBR electrode incorporates a diffuser layer, serving as a transparent front electrode.

“The AZO diffuser layer was chemically etched, and the light-scattering structure was controlled by varying the etching time,” the researchers said. “As the etching time increased, the reflectance spectra tended to decrease over the entire wavelength range, owing to the textured surface of the diffuser layer.”