Fundamental material properties become highly susceptible to external perturbations in low dimensions. This presents tremendous new opportunities for manipulating the behavior of novel 2D layered materials and ultimately achieving unprecedented control over their performance when integrated into highly specific functional devices. However, strategies that enable such control are sorely lacking to date and remain an outstanding challenge for the materials science community. Progress here requires of a comprehensive microscopic picture of the fundamental properties of 2D materials in clear connection to their macroscopic behavior, a knowledge that is still missing due to the lack of experimental techniques that simultaneously probe multiple length regimes. The main objective of the proposed research is to demonstrate control over the electronic ground states of 2D materials via external strain and electromagnetic fields to build links of applicability for signal processing in electromechanical nanodevices. We will focus on 2D correlated materials exhibiting collective electronic phases such as superconductivity, which respond dramatically to external perturbations. The project aims to understand the interplay between these external stimuli and microscopic electronic phases, and to unambiguously correlate them with mesoscopic electrical transport and mechanical response. This project comprises three research thrusts: (i) Development of new instrumentation that provides a direct way to correlate atomic-scale and mesoscopic properties of materials, and to establish links between (ii) the electrical conductivity and (iii) the mechanical response of 2D correlated materials with their atomic-scale structure and stimulus-dependent electronic phase diagram. This project has the potential to transform this field by providing new pathways to control the behavior of layered nanostructures.

The use of light to activate anticancer prodrugs is nowadays a reality in clinics around the world. Photodynamic therapy is an effective treatment for the localised destruction of cancer cells in a range of tissues and organs. Triggering the antiproliferative activity of chemotherapy agents with spatial and temporal control offers the advantage of reducing side effects and resistance. On the bases of the great success of metal-based drugs (e.g. cisplatin and its derivatives), photoactivatable metal complexes have been investigated for their potential in light-activated therapy. This promising class of molecules is characterised by outstanding photophysical and photochemical features, which can result in novel cytotoxicity mechanisms. Among transition metals, gold has shown promising anticancer features, however no attempt to exploit Au photochemistry for medicinal use has been reported yet. This project aims at exploring such potential by investigating the development of innovative photoactivatable gold complexes that can be used as effective prodrugs for photochemotherapy and simultaneously act as imaging agents. In particular, the research plan involves the synthesis of novel gold(III) carbene complexes which display dark stability in physiological conditions and high reactivity under light irradiation. These systems can undergo controlled Au(III)/Au(I) reduction in cell compartments giving new cell killing modes and therapeutic advantages. Strikingly, their remarkable synthetic and chemical versatility are ideal for combining therapy and imaging capabilities through labelling with 124-I radionuclide for Positron Emission Tomography (PET). Integration of such features has the potential to deliver innovative image-guided agents for cancer phototherapy.

With the advent of self-assembly, increasingly high hopes are being placed on supramolecular materials as future active components of a variety of devices. The main challenge remains the design and assembly of supramolecular structures with emerging functionalities tailored according to our needs. In this respect, the extensive research over the last decades has led to impressive progress in the self-assembly of molecular structures. However, self-assembly typically relies on non-covalent interactions, which are relatively weak and limit the structure’s stability and often even their functionality. Only recently the first covalently bonded organic networks were synthesized directly on substrate surfaces under ultra-high-vacuum, whose structure could be defined by appropriate design of the molecular precursors. The potential of this approach was immediately recognized and has attracted great attention. However, the field is still in its infancy, and the aim of this project is to lift this new concept to higher levels of sophistication reaching real functionality. For optimum tunability of the material’s properties, its structure must be controlled to the atomic level and allow great levels of complexity and perfection. Complexity can be reached e.g. with hybrid structures combining different types of precursors. In this project, this hardly explored approach will be applied to three families of materials of utmost timeliness and relevance: graphene nanoribbons, porous frameworks, and donor-acceptor networks. Along the pursuit of these objectives, side challenges that will be addressed are the extension of our currently available chemistry-on-surfaces toolbox by identification of new reactions, optimized reaction conditions, surfaces, and ultimately their combination strategies. A battery of tools, with special emphasis on scanning probe microscopies, will be used to visualize and characterize the reactions and physical-chemical properties of the resulting materials.

Coherent Elastic Neutrino-Nucleus Scattering (CEνNS) is a recently demonstrated novel process of neutrino interaction. It provides numerous avenues to advance our sensitivity to new nuclear and particle physics beyond the Standard Model while simultaneously allowing a dramatic miniaturization of otherwise massive neutrino detectors, opening up the possibility of technological applications. Both the supervisor and the partner organization host, along a number of collaborators, recently proposed to use the neutrino flux from the upcoming European Spallation Source (ESS) for a definitive exploration of all phenomenological opportunities provided by CEνNS. The proposal includes a variety of detection techniques to evaluate such a process including the use high-pressure gaseous xenon (HPGXe) chambers and cryogenic undoped CsI scintillator crystals. For reasons of nuclear structure, CsI and Xe detectors are identical in their response to CEνNS. However, the technologies and their expected systematics are fully different. Simultaneous use at the ESS will therefore provide robust confirmation for any possible signatures of new physics. During the outgoing phase (OP) the researcher will take part in the development and characterization of a 31.5 Kg cryogenic undoped CsI array which will be later deployed in ESS. While HPGXe detectors are a mature technology, their response to nuclear recoils in the energy range of CEνNS is unknown. Characterizing the response in such range is one of the main goals of this proposal and the methodology to do so will be developed during the OP. In the incoming phase, the researcher will implement the techniques developed during the OP in a small HPGXe chamber currently being built in DIPC. The studies will be repeated in a larger demonstrator in which he'll take a leading role in the design and deployment. Finally, the researcher will evaluate, through simulation and on-site measurements, the neutron background for CEνNS searches at ESS.

This project presents a new technology for detectors used in positron emission tomography (PET), based on liquid xenon instead of current scintillator crystals. The basic element is a liquid xenon scintillating cell, with its size optimized to maximize the number of gammas that interact in the cell. Silicon photomultipliers read out by low power, low noise customized integrated circuits for time of flight applications will be used as sensors. Xenon is a noble gas which scintillates as response to ionizing radiation. Scintillation is very fast and intense, which results in the possibility of building a PET of good energy and spatial resolution and excellent time resolution. This, in turn, makes possible the measurement of the time-of-flight (TOF), which increases the sensitivity of the detector. Recently, the PI has published a Monte Carlo study of the coincidence resolving time that can be achieved by the PETALO technology, obtaining the promising result of less than 100 ps FWHM, which would be a break-through in the PET scanner field. The low cost of liquid xenon compared to conventional scintillating crystals opens two possible applications: one one hand, a full body PET reducing the cost and with an already better performance than the current technology; on the other hand, a smaller brain scanner, optimized to maximize the improvement in the performance with TOF measurements. This project will demonstrate the technological and commercial feasibility of the proposed technology. For this purpose, first a set of prototypes with two cells will be built to evaluate the resulting performance of the PETALO technology using different kinds of photosensors (UV light sensitive SiPMs versus conventional ones coated with a wavelength shifter). In a second phase, a full ring of the dimensions of a brain scanner will be built, using the technology that has performed better according to the results of this first phase.