Novel light response makes material with promise for sensors

According to NC State, this is the first time that researchers have demonstrated a material that performs efficiently in response to this light range. 

At play is a phenomenon called surface plasmon resonance, where researchers illuminate the interface between a conducting and an insulating material. If the angle, polarisation, and wavelength of the incoming light are just right, electrons in the conductor will oscillate. This oscillation creates an electric field extending into the insulator that can be applied to biomedical sensors, solar cells, and opto-electronic devices.

The wavelength of light that causes these oscillations depends on the nature of the conductive material.

Materials with a high density of free electrons respond to short wavelengths of light, such as those in the ultraviolet range. Materials with lower electron density (such as conventional semiconductors) respond to long wavelengths of light, such as those in the far IR. Until now, however, scientists were unable to identify materials that could support efficient surface plasmon resonance when targeted with wavelengths of light in the mid-IR range.