Nanotechnology Research Group

Novel Sensor Technologies for PAT

A method for the determination of the concentration of enantiomers in process fluids will be determined via a Molecularly Imprinted Polymer (MIP) type sensor having a specific affinity for the target molecules under test. The uptake of molecules by the MIP will be determined via novel nanohole plasmon resonance sensing technologies and more conventional quartz crystal microbalance (QCM) methods.
The project will develop novel turn key methods based on colloidal nanolithography for the fabrication of isolated nanoholes in thin films of gold. The fabrication of structured periodic arrays of nanoholes showing long range order will also be developed. Methods based on silane chemistry will allow the size and periodicity of the nanohole arrays to be tightly controlled. Extraordinary optical transmission through these holes will be measured via dark field spectroscopy and the effects of the hole diameters and their periodicity on the peak transmission wavelength will be determined.
The change in refractive index at the surface of the nanohole film due to the uptake of target molecules by the MIP will modify the transmission of light through the nanohole structures resulting in an optical signal that relates to the concentration of target molecules in the test sample.   
A QCM having an MIP coating will be used to determine the number of molecules entering the MIP over time via an absorption isotherm. The efficacy of both techniques  within the context of industrial deployment will be assessed.
Modelling of the colloidal nanolithography process, the extraordinary optical transmission through the nanohole structures and the interaction between the MIP and target molecules will allow a deeper understanding of the processes involved and will assist in the deployment of these sensors as a PAT compliant method with enantiometric selectivity.  

Nanoscale Characterisation of Organic Photovoltaic Structures

Photovoltaic technologies based on organic polymers can be produced at lower costs than any other solar technology, mass production via roll to roll manufacturing processes mitigates  high demand and paves the way for new business models and funding mechanisms. It is widely anticipated that print based production technologies will achieve costs of less than €1 Wp^-1 soon after commercialisation, but will produce modules with an electricity generating lifetime that is significantly shorter than that offered by silicon technologies. To ensure the viability of this technology in an Irish context a guaranteed module lifetime of better than 10 years is necessary.
Photovoltaic polymers currently exhibit lifetimes that are significantly shorter than the required minimum of 10 years and have lower efficiencies than commercial silicon based technology. To improve their viability it is necessary to either increase their lifetime or their efficiency. The performance of these devices are dominated by events occurring at the nanoscale.  The ability to relate the nanoscale morphology of these devices to their charge transport properties and to thereby identify the mechanisms that lead to device failure is  important in this regard. Methods for the nanoscale characterisation of these devices based of scanning probe microscopy, FTIR spectroscopy and fluorescence imaging are currently under development.