Optimising scanning probe microscopy
Scientists of the EU-funded project 'Functional semiconductor nanowire probes' (FUNPROB)(opens in new window) are working on developing semiconductor-based nanowires (NWs) to enhance SPM sensor functionality, sensitivity and resolution. They comprehensively characterised properties of different III-V semiconductor materials including Gallium (Ga), Arsenic (As) and Manganese (Mn). Their growth on different types of complex substrates was studied to determine and fine-tune NW properties for SPM probe fabrication. Researchers successfully developed NW arrays of (Ga,Mn)As on a GaAs(100) substrate using molecular beam epitaxy — the first of its kind. Besides this, growth properties of other materials including Ga nitride systems were characterised in depth. Material properties and behaviour in nanostructures and discrete functional theory calculations were used to develop accurate models, predict growth kinetics and synthesise NWs. FUNPROB members developed a platform for nano-scale characterisation of materials using different microscopy and other state-of-the-art techniques. This platform aided in advanced prefabrication, scanning thermal microscopy characterisation, mapping of nanomechanical proprieties and advanced sample preparation for interface characterisation. Such active feedback from NW growth, characterisation and modelling helped optimise control of optical and structural properties. Currently, they are working on modelling thermal energy transport and interface phenomena. Scientists fabricated modified SPM tips with carbon NWs and demonstrated their enhanced resolution and precision during nanolithography, nanosurgery of erythrocytes and manipulation of colloidal particles. Using focused ion beam, they attached carbon nanotubes to SPM sensor tips and demonstrated their superior thermal and spatial resolution during thermal and topographical measurements. Already, within the first project period, project activities have led to publication of 31 peer-reviewed papers and several conference papers. FUNPROB members delivered over 20 invited lectures and participated in five symposia. Future applications will include the electrical detection of pathogens such as viruses in sectors like biomedical diagnostics and environment monitoring.
