Flexible graphene THz detector
- Auteur:Ella Cai
- Relâchez le:2017-11-02
THz radiation can be detected by graphene FETs fabricated on a flexible polymer substrate, according to Chalmers University in Sweden.
At room temperature, it detects signals from 330 to 500GHz.
According to “A flexible graphene terahertz detector” in Applied Physics Letters, estimated noise equivalent power in the antenna-coupled graphene FETs at room temperature is below 3nW/√Hz at 487GHz.
A bow tie antenna around 150μm across (just visible within photo of fingerprint-sized antenna array) feeds the gate and source of the graphene FET – with 5.5μm gate length and 4μm channel width – the co-planar drain connection comes out through the centre of the gate antenna.
Bending has a noticeable effect on response, but does not stop the device working, said the university. Mathematical models predict the right order or response under bending.
With an array of detectors, the team proposes that a THz camera might be possible.
The single-layer graphene used was created using CVD then patterned by electron beam lithography.
SOurce and drain electrodes are layers titanium paladuim gold. Aluminium was oxidesed to form insulation layers.
In the experimental set-up, THz radiation was focussed onto the detector using PTFE and silicon lenses.
Research on the terahertz detector has been funded by the EU Graphene Flagship, the Swedish Foundation for Strategic Research (SSF), and the Knut and Alice Wallenberg Foundation (KAW).
At room temperature, it detects signals from 330 to 500GHz.
According to “A flexible graphene terahertz detector” in Applied Physics Letters, estimated noise equivalent power in the antenna-coupled graphene FETs at room temperature is below 3nW/√Hz at 487GHz.
A bow tie antenna around 150μm across (just visible within photo of fingerprint-sized antenna array) feeds the gate and source of the graphene FET – with 5.5μm gate length and 4μm channel width – the co-planar drain connection comes out through the centre of the gate antenna.
Bending has a noticeable effect on response, but does not stop the device working, said the university. Mathematical models predict the right order or response under bending.
With an array of detectors, the team proposes that a THz camera might be possible.
The single-layer graphene used was created using CVD then patterned by electron beam lithography.
SOurce and drain electrodes are layers titanium paladuim gold. Aluminium was oxidesed to form insulation layers.
In the experimental set-up, THz radiation was focussed onto the detector using PTFE and silicon lenses.
Research on the terahertz detector has been funded by the EU Graphene Flagship, the Swedish Foundation for Strategic Research (SSF), and the Knut and Alice Wallenberg Foundation (KAW).
