Synthesis and properties of silicon quantum dots

Project funded by Swedish Research Council (Project grant), grant 2015-04064_VR. Participating organisations named by the source: KTH, Royal Institute of Technology. Funded amount: SEK 3,080,000, as stated by the source. Runs 2016-01-01 to 2019-12-31. Keywords: Teknik, Engineering and Technology, Nanoteknik, Nano-technology. Source: OpenAIRE Graph, from the funder's project data (collected by OpenAIRE on 2025-12-06); national funding data, not CORDIS. Abstract given by the source: This proposal is a continuation of a previous VR project focusing on the physics of silicon quantum dots. Whereas the properties of direct bandgap quantum dots are quite well known relatively little is known of the Si quantum dots. This is largely because the bandgap is still of indirect nature resulting in very long exciton decay times and correspondingly low brightness, but also because chemical synthesis is not as straight-forward as e.g. for CdSe quantum dots. Applications of Si quantum dots are as phosphors for white light emission, for improved color rendering in displays or as non-toxic labelling of bio molecules. In the project we will fabricate Si quantum dots essentially along two different routes: (i) By a top down approach using e-beam lithography, plasma etching and careful oxidation. The resulting regular arrays of quantum dots can be characterized by single-dot spectroscopy using a cooled CCD camera or using an avalanche photodiode for time decays and photon statistics. (ii) By chemical synthesis using a Si rich compound (HSQ - hydrogen silsesquioxane), a high thermal anneal and subsequent release of Si nanocrystals followed by passivation. This is a mass fabrication technique, suitable for applications, which has demonstrated very high quantum yields (up to ~65 %). But by dilution and spin coating single-dot spectroscopy may still be performed on individual nanocrystals. So far we have demonstrated ultra-narrow emission lines at low temperatures, characterized on/off blinking, measured exciton lifetimes of individual dots and characterized Auger recombination at high injections. In the continuation of the project we will perform correlated studies of size (AFM, TEM) and PL spectra for single quantum dots. We also intend to look at absorptive states using PLE (PL excitation spectroscopy) and tunneling spectroscopy to reveal the absorption and luminescence mechanism. Finally, we will also address silicon quantum well luminescence at decreasing [shortened; the full text is on the OpenAIRE page]

Original source.

Source: OpenAIRE Graph: projects of national funders, OpenAIRE, from the project data of Swedish Research Council. Retrieved 2026-10-28. Licence: Creative Commons Attribution 4.0 (OpenAIRE Graph). Selected metadata, adapted presentation; the publisher's record is authoritative. No endorsement by the source is implied. Licence: Creative Commons Attribution 4.0 (CC BY 4.0).

AI-assisted summary: A project funded by the Swedish Research Council, involving KTH, Royal Institute of Technology, to study silicon quantum dots for applications in lighting and bio-labeling, with a budget of SEK 3,080,000 from 2016 to 2019. Suggested technology pillar: enabling. Generated by AI from the public source text; it may contain errors and the original source is authoritative.