Surface-plasmon-coupled emission enhancement of a quantum well with a metal nanoparticle embedded in a light-emitting diode

Abstract

The coupling behavior of an InGaN/GaN quantum well (QW), which is assumed to consist of an array of radiating dipoles, with the induced localized surface plasmon (LSP) resonance on an Ag nanosphere (NS) embedded in the p-type layer of a nitride light-emitting diode is demonstrated. The numerical study of the coupling behavior of an individual radiating dipole is based on an algorithm, which takes account of the induction of LSP resonance on the Ag NS by the radiating dipole and the feedback of the LSP resonance to the behavior of the radiating dipole. In this study, we first evaluate the enhancements of dipole strength and radiated power in such a coupling process for the dipoles oriented along the radial and orbital directions with respect to the Ag NS under the conditions of different distances between the radiating dipole and Ag NS. Then, the QW coupling effect is obtained through the superposition of those of the individual dipoles in the array. It is found that both the LSP dipole resonance and higher-order resonance can contribute significant radiated power enhancements to the QW-LSP coupling system.

The Coupling Behavior of Multiple Dipoles and Localized Surface Plasmons in Ag Nanoparticles Array

“…2 The schematic structure of the PhC-Ag LED in 3D FDTD simulation. There are five dipoles coupled with LSP in Ag NPs include the dipole-MQW approximation [7,10,13], location and polarization of dipole approximation [11,15], single Ag NP approximation and simplification of the simulated LED model approximation [8,16], and so on. If the approximations are considered strictly, the calculation volume will become too huge to be carried out.…”

“…The proportion of the dissipated energy to extracted energy of LSP and multiple quantum well (MQW) coupling will determine either enhancement or suppression of the emission efficiency [5]. Many approaches have been proposed to decrease the dissipated energy by LSP, such as the metal morphology adjustment [6], distance optimization between the quantum well and metal particles [7], coupling among LSPs in neighbor metal particles [8], excitation of the LSP-QW system by e-beam in cathodoluminescence (CL) [9], and coupling of both the radial and orbital dipoles with LSP [10,11].…”

“…Yang et al have considered the feedback effect of the LSP resonance field on the radiating dipole behavior [10,11,14,15]. Their simulations reveal that not only the internal quantum efficiency (IQE) but also the light extraction efficiency (LEE) of a light-emitting diode (LED) can be enhanced via LSP coupling.…”

Further reduction of efficiency droop effect by adding a lower-index dielectric interlayer in a surface plasmon coupled blue light-emitting diode with surface metal nanoparticles

“…Although SP coupling in an light-emitting diode (LED) can lead to the advantages of internal quantum efficiency (IQE) enhancement, 1-4 efficiency droop reduction, 4,5 and polarized output generation, 4,6 the effective operation of SP coupling is mainly in the green-yellow range because in most Ag nanostructures for inducing localized surface plasmon (LSP) resonance, the fundamental resonance mode (dipole resonance) is located in the yellow-red spectral range. [7][8][9] The fundamental resonance mode, which can usually induce a stronger SP coupling effect, is more red-shifted if the metal nanostructures are surrounded by the LED semiconductor. 10,11 In this situation, although we can still use a higher-order resonance mode for induce SP coupling in the blue-green spectral range, its weaker resonance strength and normally higher metal dissipation usually result in a weaker SP coupling effect.…”

Numerical Study of Polarization-Dependent Emission Properties of Localized-Surface-Plasmon-Coupled Light Emitting Diodes with Ag/SiO2 Na

“…Recently, researchers have paid attention to polarization of light emission in SP-coupled LEDs. Most reports are related to the Ag NP buried in the p-GaN layer, where the enhancement of the radiation power of the dipole near the Ag NP is dramatically changed by the direction of the dipole radiation [20][21][22]. However, the Ag NP embedded structure has several issues for the real LED device because of the irregular Ag NP size caused by the high temperature during the epitaxial process and the degradation of the crystal quality due to the Ag NPs.…”