Periodic Reporting for period 2 - NANOLED (Toward single colloidal nanocrystal light-emitting diodes)
Okres sprawozdawczy: 2021-07-01 do 2022-12-31
Project NANOLED aims at developing novel electronic devices capable of single photon emission. Such devices will exploit the light-emission properties of colloidal semiconductor nanocrystals: a class of nanomaterials whose “small-size” controls the emission of a semiconductor. Importantly, a single colloidal semiconductor nanocrystal is an intrinsic single-photon emitter, making this class of nanomaterials the ideal playground for the design of novel devices and technologies for quantum light-sources.
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
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
During the first half of the project, the research team focused on the following aspects of project development:
- 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.
- 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.
During the first half of the project, NANOLED has demonstrated various breakthroughs compared to the state-of-the-art. The fabrication of a large array of single nanocrystals (NCs) with controlled position represents a considerable step forward, as the method for fabricating it is extremely versatile and it can be employed with a large variety of NCs with various shape and/or composition. In addition, the developed NCs positioning method allows correlating morphological data to optical data and it is compatible with electrical injection. The combination of all these properties leads to an advanced and versatile platform that can be used for both fundamental studies as well as applications.
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.
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.