Periodic Reporting for period 2 - NANOLED (Toward single colloidal nanocrystal light-emitting diodes)
Reporting period: 2021-07-01 to 2022-12-31
Single-photon sources are a core component of all quantum technologies currently under development. Nevertheless, single photon generation still require further control or improvement and investigation of novel device architecture or materials can have a dramatic impact on the performance of quantum technologies.
Project NANOLEDS objectives are as following:
- Identification of the best colloidal semiconductor nanocrystal candidates for single-photon generation
- Development of tools for the fabrication of light-emitting diodes based on single nanocrystals
- synthesis of Perovskite nanocrystals with controlled dimensions and controlled emission properties
- synthesis and functionalization of core-shell CdSe/CdS nanocrystals
- characterization of the obtained materials
- self-assembly of individual emitting Perovskite nanocrystals with optically inactive nanocrystal for the formation of single-photon emitting structures with large area
- positioning of invididual nanocrystals onto a substrate via patterning and functionalization of the latter.
Other significant achievements have been obtained in material development. The team demonstrated that it is possible to carry out ligand-exchange on perovskite NCs in solid-state, thus improving the photoluminescence quantum yield compared to the pristine material and the standard ligand-exchange carried out in solution. The ligand-exchange in solid-state enables the fabrication of homostructures trough spin-coating layer-by-layer (lbl) deposition. The LbL assembly method results in high quality films, whose thicknesses can be finely controlled. Finally, other breakthroughs are represented by the novel IR-emitting materials prepared within the project framework, namely CsxMnBry NCs and InAs/Znse. The latter represents a considerable step forward compared to the state-of-the-art since the synthetic approach based on ZnCl2 leads to the formation of high-quality NCs with photoluminescence quantum yield above 40%.
Considering the various results during the first half of the project, the research team should demonstrate an electrical injected single-photon-source based on deterministically positioned NCs by the end of the project or soon afterward. In addition, taking into account the combination of the fabrication tools developed and the novel materials synthesized, the research team expects to fabricate novel nano-sized light sources (not only single-photon emitting devices) operating both in visible and near-infrared spectral ranges.