Design of a tandem distributed Bragg reflectors specialized for enhancing the efficiency of GaN-based ultraviolet light-emitting diodes

•Design a type of tandem DBR that shows advantages over normal DBR in ultraviolet region.•The use of the tandem DBR (centered at 390 nm) enhances the extraction efficiency without detuning the cavity and meanwhile narrows the spectral width of the emitted light.•Demonstrate the potential that the tandem DBRs (centered at 343 nm and 246 nm respectively) have for enhancing the efficiency in deep UV device.

We design a type of “tandem distributed Bragg reflector (DBR)” that shows advantages over normal DBR in ultraviolet region. We apply a tandem DBR centered at 390 nm to a resonant cavity light emitting diodes model, consequently enhancing the extraction efficiency without detuning the cavity while narrowing the spectral width of the emitted light. The extraction efficiency into a numerical aperture exhibits a 36% increase compared to that of the normal structure. We further demonstrate the potential that the tandem DBRs (centered at 343 nm and 246 nm respectively) have for enhancing the efficiency in GaN-based deep UV device.