High-efficiency staggered 530 nm InGaN/InGaN/GaN quantum-well light-emitting diodes

Abstract

Optical properties of staggered 530 nm InGaN/InGaN/GaN quantum-well (QW) light-emitting-diodes are investigated using the multiband effective mass theory. These results are compared with those of conventional 530 nm InGaN/GaN QW structures. A staggered InGaN/InGaN/GaN QW structure is shown to have much larger spontaneous emission than a conventional InGaN/GaN QW structure. This can be explained by the fact that a staggered QW structure has much larger matrix element than a conventional QW structure because a spatial separation between electron and hole wave functions is substantially reduced with the inclusion of a staggered InGaN layer. A staggered QW structure shows that the peak position at a high carrier density (530 nm) is similar to that at a noninjection level.

Correlating electroluminescence characterization and physics-based models of InGaN/GaN LEDs: Pitfalls and open issues

“…The spectra are normalized, as the adopted model for broadening does not affect the total generated optical power or the IQE. The inclusion of many-body Coulomb interactions [86][87][88][89][90][91][92] as implemented in the present versions of the simulators has not resulted, with the exception of E g renormalization, in a real improvement in their predictive capabilities, due to the large set of widely-adjustable empirical parameters involved in the corresponding models.…”

Cathodoluminescence characteristics of linearly shaped staggered InGaN quantum wells light-emitting diodes

“…The charge separation reduces the electron-hole wavefunction overlap (Γ e_hh ) in InGaN QW, which leads to significant reduction in its radiative recombination rate (~ | Γ e_hh | 2 ). Several approaches have been proposed to enhance the overlap Γ e_hh such as 1) non-polar InGaN QW [24], 2) InGaN QW with δ-AlGaN layer [25,26], 3) staggered InGaN QW [27][28][29][30][31][32][33][34][35][36][37], 4) type-II InGaN-GaNAs QW [38][39][40], and 5) strain-compensated InGaNAlGaN QW [41,42].…”

Surface plasmon dispersion engineering via double-metallic Au/Ag layers for nitride light-emitting diodes

“…Several approaches have been demonstrated to suppress the charge separation in polar InGaN QWs by employing novel QWs with improved electron-hole wave function overlap (Γ e_hh ), as follows 1) staggered InGaN QW [5][6][7][8][9][10][11][12][13][14], 2) type-II InGaN-GaNAs QW [15,16], 3) strain-compensated InGaN-AlGaN QW [17,18], 4) InGaN QW with embedded δ-AlGaN layer [19,20], and 5) triangular InGaN QW [21].…”