Recently, the surface of the wings of the Psaltoda claripennis cicada species has been shown to possess bactericidal properties and it has been suggested that the nanostructure present on the wings was responsible for the bacterial death. We have studied the surface-

. (2016). Fabrication and characterisation of GaAs nanopillars using nanosphere lithography and metal assisted chemical etching. RSC Advances: an international journal to further the chemical sciences, 6 30468-30473.Fabrication and characterisation of GaAs nanopillars using nanosphere lithography and metal assisted chemical etching AbstractWe present a low-cost fabrication procedure for the production of nanoscale periodic GaAs nanopillar arrays, using the nanosphere lithography technique as a templating mechanism and the electrochemical metal assisted etch process (MacEtch). The room-temperature photoluminescence (PL) and Raman spectroscopic properties of the fabricated pillars are detailed, as are the structural properties (scanning electron microscopy) and fabrication process. From our PL measurements, we observe a singular GaAs emission at 1.43 eV with no indications of any blue or green emissions, but with a slight redshift due to porosity induced by the MacEtch process and characteristic of porous GaAs (p-GaAs). This is further confirmed via Raman spectroscopy, where additionally we observe the formation of an external cladding of elemental As around our nanopillar features. The optical emission is enhanced by an order magnitude (~300%) for our nanopillar sample relative to the planar unprocessed GaAs reference. We present a low-cost fabrication procedure for the production of nanoscale periodic GaAs nanopillar arrays, using the nanosphere lithography technique as a templating mechanism and the electrochemical metal assisted etch process (MacEtch). The room-temperature photoluminescence (PL) and Raman spectroscopic properties of the fabricated pillars are detailed, as are the structural properties (scanning electron microscopy) and fabrication process. From our PL measurements, we observe a singular GaAs emission at 1.43 eV with no indications of any blue or green emissions, but with a slight redshift due to porosity induced by the MacEtch process and characteristic of porous GaAs (p-GaAs). This is further confirmed via Raman spectroscopy, where additionally we observe the formation of an external cladding of elemental As around our nanopillar features. The optical emission is enhanced by an order magnitude ($300%) for our nanopillar sample relative to the planar unprocessed GaAs reference.

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For a sustainable human presence on the Moon, it is critical to develop technologies that could utilise the locally available resources (a.k.a. in situ resource utilisation or ISRU) for habitat construction. As the surface soil is one of the most widely available resources at the Moon, we have investigated the viability of microwave heating of a lunar soil simulant (JSC-1A). JSC-1A was thermally treated in a bespoke microwave apparatus using 2.45 GHz frequency, using five different microwave powers in the range of 250 W to 1000 W. The structural properties of the resulting products were analysed to determine whether their microstructures and mechanical strengths differ under different input powers; and whether input power plays a crucial role in triggering thermal runaway, for identifying the optimum power for developing a microwave-heating. Our key findings are: (i) the higher input powers (800 W and 1000 W) generate the highest yields and microstructures with the greatest mechanical strengths, at the shortest fabrication times, and (ii) thermal runaway improves the microwave heating efficiency despite the rapid increase in temperature, once it is triggered. Our findings are of key importance for developing a microwave-heating payload for future lunar ISRU demonstration missions, contributing towards 3D printing-based extra-terrestrial construction processes.

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We present details of the deposition of transparent and earth-abundant p-type CuBr films with high hole conductivity and the fabrication and characterization of a prototype solar cell based on p-CuBr/n-Si

A more than 70% enhancement in the thermoelectric power factor of single-crystal silicon is demonstrated in silicon nano-films, a consequence of the introduction of networks of dislocation loops and extended crystallographic defects. Despite these defects causing reductions in electrical conductivity, carrier concentration, and carrier mobility, large corresponding increases in the Seebeck coefficient and reductions in thermal conductivity lead to a significant net enhancement in thermoelectric performance. Crystal damage is deliberately introduced in a sub-surface nano-layer within a silicon substrate, demonstrating the possibility to tune the thermoelectric properties at the nano-scale within such wafers in a repeatable, large-scale, and cost-effective way.