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
k
middot
p
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 In
x
Ga
_1-

x
N/In
y
Ga
_1-

y
N QW and three-layer staggered In
y
Ga
_1-

y
N/In
x
Ga
_1-

x
N/In
y
Ga
_1-

y
N 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 In
z
Ga
_1-

z
N 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.