Nanoelectronics and Terahertz Devices Group

Nanoelectronics and Terahertz Devices Group

 

GaN-based Gunn Terahertz sources

In many applications in the field of sensor and imaging technologies small Terahertz (THz)-radiation sources are required to emit stable in frequency narrowband electromagnetic radiation. For the envisaged frequency range between 100 GHz to 700 GHz there are presently no cost-effective, compact and narrow-band THz sources with high output power available. The THz sources based on the new GaN Gunn diodes will fill this gap and help the THz-radiation to become a breakthrough technology especially for the following spectroscopic and imaging applications.

Nanostructured Terahertz Schottky detectors

A new fully integrated THz Schottky detector based on vertically contacted high doped gallium arsenide (GaAs) by using a small diameter (100 nm) silver nanowire (NW) as air-bridge contact. Compared to Schottky diodes with evaporated metal contact it has lower capacitance (0.5 fF) for a high cut-off frequency as well as better zero-bias operation for a lower noise value.

Carbon nanotube (CNT) Sensors

Unique artificial-hair-cell-type sensor (AHCTS) based entirely on 3D-structured, vertically aligned carbon nanotube (CNT) bundles: The integrated 3D CNT sensor can detect three-dimensional forces using the deflection or compression of a central CNT bundle which changes the contact resistance to the shorter neighboring bundles.

Carbon nanotube (CNT) THz sources

A new miniature black-body radiator with fast electrical modulation capability was fabricated using carbon nanotube (CNT) yarns (Ø 20-100 μm). The small diameter of the yarn allows a fast pulsed-modulation (> 100 Hz) without the need of a mechanical chopper. Furthermore, the single CNT yarn handles reliably high currents > 100 mA for high power operation. It can be used in an array configuration with integrated filters and collimator lenses. Thus, these CNT yarns can be applied as electrically modulated broadband THz source for monitoring of e.g. packages in production lines, characterization of broadband THz filters and detectors as well as secure thermal infrared communication.

Projects:

  1. Pioneer Fund – Activator: The university-internal funding program Pioneer Fund aims to increase TU Darmstadt’s capacity for Innovation. The Pioneer Fund finances these development- and validation activities in projects lasting up to 18 months.
  2. DFG Project: The Deutsche Forschungsgemeinschaft (DFG) project was granted in 2015. The proposal was suggested future work for optimization the nanoelectrodes based THz photomixers.