Optical, Microstructural, and Electrical Properties of Multilayers-based Al/Ag Thin Films for Futuristic Nano-photonic Devices

We propose to present our latest results on the successful fabrication, characterization, and analysis of unique multilayers (ML)-based Al/Ag thin films with enhanced optical and microstructural properties. Supportive data for our findings is based on AFM, SEM, and IV measurements along with optical spectral analysis. Among the immediate applications for the proposed thin films is in the development of nano photonics via near-field optical sensors.

Unlike the conventional approach for the development of AlAg-based reflective alloys, our approach exploits the distinctive characteristics of individual Al and Ag thin films. In this work, we investigated the possibility of concatenating Al and Ag thin films to produce a single composition with exceptional optical and microstructual (surface, grain size, grain boundaries) properties. Our results include an {Al(22.6 nm)/Ag(19.4 nm)}x3/Al(22.6 nm) composition, which exhibits virtually uniform reflective properties throughout the visible spectrum with relative enhancements in surface roughness, grains size and grain boundaries.

One of the main reasons optical near-field transducers with nanoscale apertures are far from ideal is light “leakage” through grain boundaries of the reflective material surrounding the nano aperture. Our proposed composition addresses this issue. Our data validates that the improved properties may well be due to the production of mismatched grains and grain boundaries between the Al and Ag layers throughout the thickness of the ML composition.