Periodic Reporting for period 1 - MOONSHOT (Colloidal Indium Arsenide quantum dots as short-wave infrared single photon emitters)
Berichtszeitraum: 2024-06-01 bis 2025-11-30
Project MOONSHOT aims at developing novel quantum light-sources (i.e. generators of single photons with controlled properties) based on colloidal nanomaterials presenting emission in the near-infrared and compliance with the European directive on the "Restriction of Hazardous Substances in Electrical and Electronic Equipment" (RoHS). Currently, generation of single-photons is carried using relatively bulky systems based on laser cooled atoms or spontaneous parametric down conversion via nonlinear crystals, or more costly approaches exploiting epitaxially grown quantum dots. Nanomaterials such as colloidal nanocrystals present light-emission properties comparable to their epitaxial counterpart combined with processing based on solution/liquid and reduced fabrication cost. Nonetheless, it is difficult to prepare colloidal nanocrystals with RoHS compliant compositions presenting emission in near-infrared, in particular in the telecommunication wavelength range (1300-1600 nm). MOONSHOT addresses this issue by proposing novel synthetic approaches to prepare indium arsenide (InAs) nanocrystals, exploiting commercially available chemical precursors and investigating their single-photon emission properties. Given the aim of the project, the research carried out encompass various disciplines, such as synthetic chemistry, optical spectroscopy and materials science.
The project focused on two different aspects of indium arsenide (InAs) nanocrystals: their synthesis and the study of their optical properties (e.g. single-photon emission). In addition, in the framework of MOONSHOT, the research team has carried out an extensive market analysis (with support from an external partner) to understand how the technologies and methodologies developed can be exploited in consumer electronic applications.
The main achievement of MOONSHOT has been the development of a novel synthetic approach to InAs nanocrystals. In fact, the research team developed an amino-arsine based one-pot synthesis of size-tunable InAs nanocrystals with emission reaching 1500 nm (patent pending); such approach is based on a novel reducing agent that enables the control growth of large InAs nanocrystals (up to 3.5 nm in size) through a hot-injection method. The method is compatible with the use of ZnCl2 as additive during synthesis, enabling the growth of a ZnSe shell at high temperature. The resulting InAs/ZnSe core/shell nanocrystals show emission up to 1500 nm with a relatively high photoluminescence efficiency. Overall, this approach marks a significant starting point to synthesize InAs-based nanocrystals with tunable emission in a fast, cheap and facile one-pot approach, all this enabled by the novel reducing agent here introduced.
In the framework of MOONSHOT, the research team has also started studying the single-photon emission properties of InAs nanocrystals. Very importantly, the investigation highlighted one main issue with the synthesized InAs nanocrystals: their susceptibility to oxidation while expose to ambient air. The degradation is particularly evident and efficient when single nanocrystals are exposed to the environment, making their study inconsistent. These considerations lead the research team to start developing novel strategies to suppress the degradation, one of them being the creation of a multi-shell based on ZnSe/ZnS able to protect the InAs cores.
Finally, the market analysis highlighted various exploitation pathways for the technology developed by MOONSHOT. In fact, the developed InAs nanocrystals are not only interesting for the fabrication of quantum light-sources but also conventional ones. Nowadays, optoelectronics in the near-infrared spectral range is gaining more importance thanks to the development of efficient and affordable photodetectors/cameras, enabling a variety of applications ranging from machine-visions systems for quality assurance to point-of-care testing. Nonetheless, many applications are still hindered by the lack of cheap and bright near-infrared light-sources that can be coupled with dedicated detectors to perform fast hyperspectral imaging or analysis. Such bottleneck could be addressed by developing commercial lamps based on InAs nanocrystals, given their performance and their compliance with the RoHS directive.
Project outcome: 1 patent application, 1 peer-reviewed manuscript published, 2 peer-reviewed manuscript submitted
The main achievement of MOONSHOT has been the development of a novel synthetic approach to InAs nanocrystals. In fact, the research team developed an amino-arsine based one-pot synthesis of size-tunable InAs nanocrystals with emission reaching 1500 nm (patent pending); such approach is based on a novel reducing agent that enables the control growth of large InAs nanocrystals (up to 3.5 nm in size) through a hot-injection method. The method is compatible with the use of ZnCl2 as additive during synthesis, enabling the growth of a ZnSe shell at high temperature. The resulting InAs/ZnSe core/shell nanocrystals show emission up to 1500 nm with a relatively high photoluminescence efficiency. Overall, this approach marks a significant starting point to synthesize InAs-based nanocrystals with tunable emission in a fast, cheap and facile one-pot approach, all this enabled by the novel reducing agent here introduced.
In the framework of MOONSHOT, the research team has also started studying the single-photon emission properties of InAs nanocrystals. Very importantly, the investigation highlighted one main issue with the synthesized InAs nanocrystals: their susceptibility to oxidation while expose to ambient air. The degradation is particularly evident and efficient when single nanocrystals are exposed to the environment, making their study inconsistent. These considerations lead the research team to start developing novel strategies to suppress the degradation, one of them being the creation of a multi-shell based on ZnSe/ZnS able to protect the InAs cores.
Finally, the market analysis highlighted various exploitation pathways for the technology developed by MOONSHOT. In fact, the developed InAs nanocrystals are not only interesting for the fabrication of quantum light-sources but also conventional ones. Nowadays, optoelectronics in the near-infrared spectral range is gaining more importance thanks to the development of efficient and affordable photodetectors/cameras, enabling a variety of applications ranging from machine-visions systems for quality assurance to point-of-care testing. Nonetheless, many applications are still hindered by the lack of cheap and bright near-infrared light-sources that can be coupled with dedicated detectors to perform fast hyperspectral imaging or analysis. Such bottleneck could be addressed by developing commercial lamps based on InAs nanocrystals, given their performance and their compliance with the RoHS directive.
Project outcome: 1 patent application, 1 peer-reviewed manuscript published, 2 peer-reviewed manuscript submitted
The main improvement of MOONSHOT with respect to the state-of-the-art is the development of InAs/ZnSe core/shell nanocrystals presenting emission up to 1500 nm. Most of synthetic approaches enable the growth of InAs nanocrystals of small size, presenting emission up to 1100 nm. On the other hand, synthetic methods based on tris(trimethylsilyl)arsine as precursor (compound that is pyrophoric and not-commercially available) do not lead to emissive large nanocrystals. For this reasons, the designing of a one-pot synthetic approach combining commercially available precursors with RoHS-compliant compositions and emission up to 1500 nm is an important improvement compared to the state-of-the-art, which might also lead to commercial applications.