Mitsubishi Develops MWIR and LWIR Graphene Sensors
Other than a graphene-based FET, there is "a light-amplifying part" that produces photoelectrons and photoholes and is placed under the graphene. At a very low temperature of, for example, 80K, the responsivity increases even more, by a factor of 100x:
Mitsubishi is also developing a LWIR sensor using a dielectric for the light-amplifying. Existing quantum-type LWIR sensors reduce thermal noise by cooling down to liquid nitrogen temperature. Mitsubishi claims that with its new method, the sensor might be able to work at room temperature:
The original article in Japanese has few more figures:
Here is an earlier Nikkei article on the same topic.