Nanoscale Photoluminescence Manipulation in Monolithic Porous Silicon Oxide Microcavity Coated with Rhodamine‐Labeled Polyelectrolyte via Electrostatic Nanoassembling. Issue 20 (2nd August 2021)

• Record Type: Journal Article
• Authors: Chen, Zhi; Robbiano, Valentina; Paternò, Giuseppe M.; Carnicella, Giuseppe; Debrassi, Aline; La Mattina, Antonino A.; Mariani, Stefano; Minotto, Alessandro; Egri, Gabriella; Dähne, Lars; Cacialli, Franco; Barillaro, Giuseppe
• Is Part Of: Advanced optical materials. Volume 9:Issue 20(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-08-02
• Subjects: electrostatic nanoassembly coating -- functionalized fluorophores -- nanoscale photoluminescence -- photonic manipulation -- porous silicon oxide microcavities; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.202100036
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Porous silicon (PSi) is a promising material for future integrated nanophotonics when coupled with guest emitters, still facing challenges in terms of homogenous distribution and nanometric thickness of the emitter coating within the silicon nanostructure. Herein, it is shown that the nanopore surface of a porous silicon oxide (PSiO2 ) microcavity (MC) can be conformally coated with a uniform nm‐thick layer of a cationic light‐emitting polyelectrolyte, e.g., poly(allylamine hydrochloride) labeled with Rhodamine B (PAH‐RhoB), leveraging the self‐tuned electrostatic interaction of the positively‐charged PAH‐RhoB polymer and negatively‐charged PSiO2 surface. It is found that the emission of PAH‐RhoB in the PSiO2 MC is enhanced (≈ 2.5× ) and narrowed (≈ 30× ) at the resonant wavelength, compared with that of PAH‐RhoB in a non‐resonant PSiO2 reference structure. The time‐resolved photoluminescence analysis highlights a shortening (≈ 20%) of the PAH‐RhoB emission lifetime in the PSiO2 MC at the resonance versus off‐resonance wavelengths, and with respect to the reference structure, thereby proving a significant variation of the radiative decay rate. Remarkably, an experimental Purcell factor F p = 2.82 is achieved. This is further confirmed by the enhancement of the photoluminescence quantum yield of the PAH‐RhoB in the PSiO2 MC with respect to the reference structure. Application of the electrostatic nanoassembling approach to other emitting dyes, nanomaterials, and nanophotonic systems is envisaged. Abstract : In this work, the nanopores of a porous silicon oxide (PSiO2 ) microcavity (MC) are conformally coated with an nm‐thick layer of a cationic light‐emitting polyelectrolyte leveraging a self‐tuned electrostatic nanoassembling approach. Robust and reliable nanoscale manipulation of the polyelectrolyte photoluminescence within the PSiO2 MC is achieved, and the occurrence of Purcell effect is observed.