for Materials Characterization
Terahertz Time-Domain Spectrometer
Large bandwidth terahertz spectrometer for contact-free conductivity and carrier life-time measurements. THz spectroscopy is based on the transmission and/or reflection of THz electromagnetic waves. This powerful and non-invasive technique allows to retrieve the complex AC conductivity of materials without the need to electrical contacts. If the sample is photo-excited with a short optical pulse, THz spectroscopy can retrieve the transient photoconductivity and the carrier life time. This characteristic enables to map the (photo-) conductivity and carrier lifetime over large areas by scanning the sample under a THz beam.
• THz bandwidth: 0.1 – 2.5 THz
• Scanning area: 10 cm2
• Spatial resolution: approx. 1 mm
• Photo-excitation wavelength: 800 nm
• Time resolution: 100 fs
(Left) Scanning electron microscope images of Ag nanowire networks with different nanowire densities for transparent electrodes. (Right) Contact free THz measurements of the far-field and near-field sheet conductance. The inhomogeneous nanowire distribution gives rise of the inhomogeneous sheet conductance that can be resolved in detail using the near-field detection.