A Generalizable Single-Chip Calibration Method for Highly Quantitative SERS via Inkjet Dispense.

We present a calibration method for quantitative surface-enhanced Raman scattering (SERS) on a single-chip based on inkjet dispense (ID-SERS). We exploit the ability of inkjet to precisely pattern microdroplets at high resolution to encode multiple standard curves on the surface of a single 1 mm SERS substrate. We demonstrate quantitative SERS measurements with a relative standard error (RSE) below 3% for aqueous solutions of 1,2-bis(4-pyridyl)ethylene (BPE), the lowest reported to date.

Terahertz and mid-infrared plasmons in three-dimensional nanoporous graphene.

Two-dimensional (2D) graphene emerged as an outstanding material for plasmonic and photonic applications due to its charge-density tunability, high electron mobility, optical transparency and mechanical flexibility. Recently, novel fabrication processes have realised a three-dimensional (3D) nanoporous configuration of high-quality monolayer graphene which provides a third dimension to this material. In this work, we investigate the optical behaviour of nanoporous graphene by means of terahertz and infrared spectroscopy.

Topologically protected Dirac plasmons and their evolution across the quantum phase transition in a (Bi(1-x)In(x))2Se3 topological insulator.

A 3D Topological Insulator (TI) is an intrinsically stratified electronic material characterized by an insulating bulk and Dirac free electrons at the interface with vacuum or another dielectric. In this paper, we investigate, through terahertz (THz) spectroscopy, the plasmon excitation of Dirac electrons on thin films of (Bi1-xInx)2Se3 TI patterned in the form of a micro-ribbon array, across a Quantum Phase Transition (QPT) from the topological to a trivial insulating phase. The latter is achieved by In doping onto the Bi-site and is characterized by massive electrons at the surface.