Performance improvement of AlGaN-based deep ultraviolet light-emitting diodes by using staggered quantum wells

The optical and physical properties of AlGaN-based deep ultraviolet light-emitting diodes (UV LEDs) with various specific designs of staggered quantum wells (QWs) are numerically investigated. Detailed analysis has been carried out on the light output power, energy band, overlap of electron and hole wavefunctions, carrier concentration, radiative recombination rate, spontaneous radiative spectrum and internal quantum efficiency. The simulated results reveal that the deep UV LEDs with the staggered quantum wells exhibit better performance than their conventional counterpart due to the diminished piezoelectric polarization fields in QWs which can increase the density of electron and hole and the overlap of the electron and hole wavefunctions, and thus enhance the radiative recombination rate.