Size-dependent coupling between localized surface plasmons and excitons in silicon nitride matrix

Abstract

The size-dependent coupling between localized surface plasmons (LSPs) and excitons within a silicon nitride (SiN(x)) matrix is investigated. A strong correlation between the photoluminescence (PL) enhancement and this resonance coupling is observed. From the analysis of the relationship between the dipolar resonance peaks of Ag nanostructures with various sizes and those of PL enhancement, we ascribe the enhancement of PL from the SiN(x) matrix by the addition of Ag nanostructures mainly to the LSP resonance coupling.

Exploiting the signatures of nanoplasmon–exciton coupling on proton sensitive insulator–semiconductor devices for drug discovery applications

“…This happens as a result of optical pumping of the oxide-insulator interface (SiO 2 -Si 3 N 4 ) and insulator trapped charges in Si 3 N 4 triggered by multiple reflections at the interface of each layer on the wafer 20 . The presence of these excitons, well established in literature 19,21 , is validated by capacitance -voltage (C-V) profiling of IS junctions This journal is © The Royal Society of Chemistry 20xx…”

“…More importantly, we show how coupling of excitons and plasmons vary by changing the sizes of gold nanoparticles (AuNPs), while characterizing the pH sensing properties of the surface. When Si 3 N 4 -based IS structures without AuNPs are exposed to white light between 400-800 nm, excitons are generated due to the radiative and non-radiative recombination of electronhole pairs in the Si 3 N 4 top layer 19 . This happens as a result of optical pumping of the oxide-insulator interface (SiO 2 -Si 3 N 4 ) and insulator trapped charges in Si 3 N 4 triggered by multiple reflections at the interface of each layer on the wafer 20 .…”

“…Briefly, by adding nanoparticles of 5, 10 and 20 nm, redshifts in the properties of Si 3 N 4 are observed. This coupling is considered as a two-step process where excitons in the Si 3 N 4 matrix first transfer their energies to LSP modes, which then outcouple to propagation modes, enhancing the optical absorbance signal from the excitons in the Si 3 N 4 matrix 19,23 . We also observe that by simply varying the thickness and composition of the insulator, the strength of this exciton-plasmon coupling can be modified, leading to versatile characteristics of the proposed biosensor platform.…”

Photoluminescence enhancement from silicon quantum dots located in the vicinity of a monolayer of gold nanoparticles

“…Some research works have observed a considerable improvement of the integrated emission intensity from silicon emitting quantum dots (SiQDs) when these are adequately coupled with nanostructured noble metal particles. [25][26][27][28][29][30][31][32][33][34][35] Therefore, the fabrication of coupled silicon-metal nanostructures could be one possible solution for the manufacture of multiple luminescent devices based on silicon. 36 However, it must be emphasized that fabrication processes to make silicon-noble metal coupling structures which show photoluminescence enhancement are not simple.…”