Nanosensing
Semiconductor nanocomposite thin films composed of noble metal nanoparticles dispersed in reactive metal-oxide matrixes for LSPR gas sensing applications

Challenge

The main challenge is the development of alternative concepts for gas sensors, with near-single molecule sensitivity, especially tailored for environmental protection purposes in the automotive sector. The project aims to develop low-cost gas sensors, based on metal-oxide semiconductor (MOS) structures, containing several types of noble metal (NM) nanoparticles (NPs), with near-single molecule sensitivity with large relevance for several industrial sectors.

Solution

The research will be focused on noble metal (NM) nanoparticles (NPs) such as Au and Ag, which are oxidation resistant and exhibit uniquely intense LSPR absorption peaks in the visible spectrum. The MOS structures will include oxides such as WO3 Ta2O5, ZnO or SnO2, that show high sensitivity to the upper mentioned gases, which are central concerns not only in automotive industry, but also in several areas of industry and consumer products and health care.
Two complementary methods will be tested to produce the nanostructured films: i) the Co-deposition using a cluster source, for Au or Ag, and reactive sputtering of metal targets in O2 atmosphere, for the matrix and; ii) Co-sputtering using a high-power impulse magnetron sputtering (HIPIMS) source, for the noble metal target, and a conventional/HIPIMS source, for the dielectric matrix (in O2 atmosphere). Fundamental understanding of the LSPR effect and systematization of the consequent sensing ability will be carried out through atomistic calculations, while advanced spectroscopy and microscopy will be used to characterize and materials and their performance so that optimized systems/configurations can be designed and subsequently tested. A proof-of-concept will be implemented and the potential for practical application will be assessed through LSPR sensor prototypes, in particular, for
automotive related ones.