Investigation of Optical and Structural Stability of Localized Surface Plasmon Mediated Light‐Emitting Diodes by Ag and Ag/SiO₂ Nanoparticles

Abstract

Localized surface plasmon (LSP) effects due to Ag and Ag/SiO2 nanoparticles (NPs) deposited on GaN/InGaN multiquantum well (MQW) light‐emitting diode (LED) structures are studied. The colloidal NPs are synthesized by a sol‐gel method and drop‐cased on the LED structures. The surface density of NPs its controlled by the concentration of the NP solution. Theoretical modeling is performed for the emission spectrum and the electric field distribution of LSP resonance for Ag/SiO2 NPs. Enhanced photoluminescence (PL) efficiency is observed in the LED structures and the amount of PL enhancement increases with increasing the surface density of Ag and Ag/SiO2 NPs. These effects are attributed to resonance coupling between the MQW and LSP in the NPs. It is also shown that the PL enhancement attainable with Ag NPs and Ag/SiO2 NPs is comparable, but the latter displays a much higher stability with respect to long‐term storage and annealing due to a barrier for NP agglomeration, Ag oxidation, and impurity diffusion provided by the SiO2 shell.

Plasmonic Transition via Interparticle Coupling of Au@Ag Core–Shell Nanostructures Sheathed in Double Hydrophilic Block Copolymer for High-Performance Polymer Solar Cell

“…4−15 Novel metal nanostructures and their alloys have been the subject of intensive research owing to their interesting plasmonic behavior, including localized surface plasmon resonance (LSPR), surface-enhanced Raman scattering (SERS), and metal-enhanced fluorescence, which are useful for various applications toward biosensors, bioimaging, catalysis, thermal therapy, and optoelectronic devices, such as solar cells and light emitting diodes. 16 −22 In particular, plasmonic metal NPs have received significant attention in polymer solar cells (PSCs) applications because their LSPR effect can lead to enhancement of incident light absorption and improvement of intrinsic scattering power for higher efficiency of solar cells. Among many novel metal NPs, gold and silver possess very effective plasmonic effects to trap incident light, which exhibit relatively strong scattering in the visible range.…”

The diffusion of Ag in GaN-based surface plasmon light-emitting diodes under different temperature annealing

“…Recently, surface plasmon (SP) coupling have drawn a lot of attention, since it can effectively enhance the IQE by offer an extra emission channel [8][9][10]. To achieve high performance SP-LEDs, one of the most important key points is to get close-distance coupling between surface plasmon and the QWs.…”

“…However, as the emission wavelength approaches to the green light region, the internal quantum efficiency (IQE) suffers an obvious loss due to poor crystal quality [2], serious quantum confined stark effect (QCSE) [3] and efficiency droop [4]. Various methods have been proposed to address the above issues [5][6][7].Recently, surface plasmon (SP) coupling have drawn a lot of attention, since it can effectively enhance the IQE by offer an extra emission channel [8][9][10]. To achieve high performance SP-LEDs, one of the most important key points is to get close-distance coupling between surface plasmon and the QWs.…”

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

“…Therefore, the LSP absorption in the Ag NP is dramatically enhanced by the ohmic loss in the Ag surface [14]. In order to avoid the absorption in the Ag surface, the Ag/SiO 2 CS structure was suggested for the efficient and reliable SP LED performance.…”

“…However, the problem in Ag NP coated LEDs is an easy oxidation of Ag which induces significant absorption of the SP mode before transition to the radiation mode. It was reported that Ag/SiO 2 core-shell (CS) coated LEDs had more consistent emission efficiency than Ag NP coated LEDs [14]. Generally, the SE rate of a dipole near a metallic structure strongly depends on the radiation direction [15].…”