Size tuning of luminescent silicon nanoparticles with meso-porous silicon membranes

Size tuning of silicon (Si) nanoparticles (NPs) with the use of meso-porous silicon (meso-PS) free-standing layers is reported for the first time. Accumulation of Si NPs inside the membrane pores during the filtering process (NP transport through the meso-PS) leads to an auto-filtration effect (called Si-by-Si (SBS) filtration) allowing more efficient size selection of the NPs. General complex fractal shape and surface chemistry of the whole porous network, layer thickness as well as a given initial NP size dispersion determine final size of the NPs in the filtered solution. Moreover, quantum of step-like NP size increasing equal to 0.12 nm was found.

PL spectra with corresponding photos of initial and filtered ethanol solutions with dispersed Si NPs.Figure optionsDownload high-quality image (61 K)Download as PowerPoint slideHighlights
► Meso-porous Si membranes was shown as efficient tool for nanoparticle (NP) size tuning.
► SBS filtration are most precise method for carry size selection of Si NPs.
► SBS filtration allows to find full discrete set of photoluminescence peaks.
► Quantum of step-like NP size increasing equal to 0.12 nm is observed.