Fabrication of surface metal nanoparticles and their induced surface plasmon coupling with subsurface InGaN/GaN quantum wells

Abstract

Based on the fabrication of Ag nanoparticles (NPs) with controlled geometry and surface density on an InGaN/GaN quantum well (QW) epitaxial structure, which contains indium-rich nano-clusters for producing localized states and free-carrier (delocalized) states in the QWs, and the characterization of their localized surface plasmon (LSP) coupling behavior with the carriers in the QWs, the interplay behavior of LSP coupling with carrier delocalization in the QWs is demonstrated. By using the polystyrene nanosphere lithography technique with an appropriate nanosphere size and adjusting the post-fabrication thermal annealing condition, the induced LSP resonance wavelength of the fabricated Ag NPs on the QW sample can match the QW emission wavelength for generating the coherent coupling between the carriers in the QWs and the induced LSP. The coupling leads to the enhancement of radiative recombination rate in the QWs and results in increased photoluminescence (PL) intensity, red-shifted PL spectrum, reduced PL decay time, and enhanced internal quantum efficiency. It is found that the observed effects are mainly due to the LSP coupling with the delocalized carriers in the QWs.

Internal quantum efficiency enhancement of GaInN/GaN quantum-well structures using Ag nanoparticles

“…[7][8][9][10][11][12][13][14] Such a nanophotonic approach has been applied to light emitting devices. [15][16][17][18][19][20][21][22]24,25 The rationale behind is that the transfer of energy from carriers in GaInN QW into localized optical plasmon supported by the metallic nanostructures will create an a afad@fotonik.dtu. additional light emission channel called plasmonic channel.…”

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

“…13 However, the reduction of metal NP size leads to a weaker SP coupling effect. 7 The other approach for blue-shifting LSP resonance spectrum is to insert a thin dielectric interlayer (DI) between a metal NP and the LED top layer with the refractive index of the DI lower than that of the LED semiconductor ($2.4 in GaN).…”

Amorphous carbon-based films with surface-plasmon-enhanced full-color photoluminescence

“…It is reported that SP coupling is particularly useful for increasing emission efficiency of a light-emitting material of inherently low IQE [34]. In other words, the PL enhancement factor of materials with low IQE is higher than that of material with high IQE.…”