Quantum communication is a transformative technology that can address our society’s need for secure communication and form the backbone for networks of quantum computers. Despite recent successes in the deployment of secure quantum cryptographic keys, the unavailability of telecom-wavelength repeaters operating at the quantum level presents a major bottleneck towards a global-scale quantum communication network. QuanTELCO will overcome this bottleneck by employing a radically transformative approach based on telecom-wavelength spin centres in silicon carbide, recently discovered by our consortium. These centres uniquely possess strong optical transitions in the telecom O-band (1260-1360 nm), in a material widely used by the micro-electronics industry. QuanTELCO will exploit a mature material platform (silicon carbide), fully compatible with standard industrial micro-electronic fabrication processes. The quantum emitters employed in QuanTELCO have optical cross sections that are orders of magnitude greater than many currently leading candidates. Their emission wavelength allows direct, low-loss propagation in existing telecom networks without the detrimental losses caused by wavelength conversion. These emitters host electronic and nuclear spins which can act as memories in quantum repeater nodes. QuanTELCO will leverage these properties to demonstrate all key elements of quantum networking. We will furthermore perform preparatory tests on existing, international telecom structure and will benchmark the spin-photon entanglement across urban-scale fibre links. QuanTELCO will distil the project results to deliver a roadmap for commercial deployment based on real-world, actionable insight. This platform will provide the breakthrough required for the creation of robust, transcontinental quantum information links, compatible with existing infrastructure, thereby ushering in the era of physically secure encryption and networked quantum computation across Europe.

Lead (Pb) based perovskite solar cells (PSCs) demonstrate a remarkable power conversion efficiency (PCE of 25.2%). Their toxicity, however, raises environmental concerns and might hinder their commercial deployment. Quest for non-toxic PSCs is still at its infancy: The PCE in Pb-free PSCs is merely around 12%, which is about one third of their radiative limit. An analysis of recent literature on the Pb-free PSCs suggests a high non-radiative recombination in them, as evidenced by their high voltage loss and a low fill factor. These non-radiative recombination losses occur due to defects in the perovskite bulk and at the perovskite/charge extraction layers (CTLs) interfaces. Significant research is being carried out to suppress bulk defects, however, systematic investigations of the photophysical and photochemical properties of perovskite/CTLs interfaces remained relatively ignored. For instance, there is no quantitative data to decouple losses in Pb-free PSCs due to bulk and interfacial defects. There is also little information on the chemical and electronic properties of the interface between Pb-free perovskites and different CTLs. This project aims to systematically investigate energetic alignment, charge transfer rates, recombination, trap density and trap depth etc. at the interfaces between Pb-free perovskites and a range of CTLs (organic, inorganic). Measuring quasi-Fermi level splitting and its correlation with open-circuit voltage will help in quantifying losses due to the different interfaces. Based on the insights gained from these investigations, the interfacial properties will be tuned via doping the CTLs or via surface passivation schemes to improve charge transfer/extraction rate. The experimental findings together with insights gained from device simulations will help us to propose an elaborated picture of the loss mechanisms in Pb-free PSCs and to design device architectures to systematically alleviate device performance.

We propose a 4-year project QLSI, Quantum Large Scale Integration in Silicon, which objective is to demonstrate that silicon spin qubits are a compelling platform for scaling to very large numbers of qubits. Our demonstration relies on four ingredients: • Fabrication and operation of 16-qubit quantum processors based on industry-compatible semiconductor technology; • Demonstration of high-fidelity (>99%) single- and two-qubit gates, read-out and initialization; • Demonstration of a quantum computer prototype, with online open-access for the community (up to 8 qubits available online); • Documentation of the detailed requirements to address scalability towards large systems >1000 qubits. To achieve these results, our consortium brings together an unrivalled multidisciplinary team of European groups in academia, RTOs and industry working on silicon-based quantum devices. These groups are committed to playing an active part in developing the industrial ecosystem in silicon-based quantum technologies. QLSI is structured in three enabling toolboxes and one demonstration and scalability activity: - the semiconductor toolbox brings together skills from the semiconductor industry such as fabrication, high throughput test and CAD (computer aided design) with the expertise of the physics community; - the quantum toolbox gathers skills from the physics community on spin and quantum properties of Si based nanostructures and on quantum engineering from theory and experience perspectives; - the control toolbox gathers teams with instrumentation skills ranging from RF signal generation, automation and set up of high throughput characterization at low temperature. The toolboxes will generate stand-alone beyond the state-of-the-art results and will generate inputs to feed the demonstrator and scalability activity, which will integrate devices, hardware and software solutions to create an online open access demonstrator, to perform hybrid computation and to analyze scalability.