About five years ago, graphene-based photodetectors moved beyond detecting the visible and near-infrared range of the electromagnetic spectrum to push into the terahertz range. This is a big deal because terahertz radiation penetrates materials that block visible and mid-infrared light. Detecting it opened up a range of potential applications in medical diagnostics, process control, and even intelligent vehicles.
Also about five years ago, we saw research that combined graphene and quantum dots to create flexible photodetectors. While these photodetectors are great for detecting waves along much of the spectrum, they couldn’t capture terahertz radiation.
Now researchers at Chalmers University in Sweden have combined flexibility and terahertz detection into one flexible, graphene-based detector that could lead to new products such as wearable terahertz sensors for medical diagnosis.
In research published in the journal Applied Physics Letters, the Chalmers researchers developed a field-effect transistor (FET) built up on a plastic substrate in which the channel is made from graphene. The resulting flexible device can detect signals in the range of 330 to 500 GHz.