Design Analysis of Staggered InGaN Quantum Wells Light-Emitting Diodes at 500–540 nm

Staggered InGaN quantum wells (QWs) are analyzed as improved active region for light-emitting diodes (LEDs) emitting at 500 nm and 540 nm, respectively. The calculation of band structure is based on a self-consistent 6-band kmiddotp formalism taking into account the valence band mixing, strain effect, and spontaneous and piezoelectric polarizations as well as the carrier screening effect. Both two-layer staggered InxGa_1- xN/InyGa_1- yN QW and three-layer staggered InyGa_1- yN/InxGa_1- xN/InyGa_1- yN QW structures are investigated as active region to enhance the spontaneous emission radiative recombination rate (R _sp) for LEDs emitting at 500 nm and 540 nm. Analysis of the spontaneous emission radiative recombination rate (R _sp) shows significant enhancement for both two-layer staggered InGaN QW and three-layer staggered InGaN QW, in comparison to that of the conventional InzGa_1- zN QW. The studies of the carrier lifetime indicate a significant reduction of the carrier lifetime for staggered InGaN QWs, which contribute to the enhancement of the radiative efficiency for both two-layer staggered InGaN QW and three-layer staggered InGaN QW LEDs emitting at 500 nm and 540 nm.