Uncooled Infrared Detector Using a Thin InAsSb Layer Acting as a Gate on a GaAs Field-Effect Transistor

The demand for high-quality low-cost uncooled infrared (IR) photodetectors have significantly increased in recent years. In this paper, a novel concept of utilizing InAsSb as a midwave IR uncooled detector is introduced. According to the approach used in this paper, the InAsSb detection layer acts as gate over a GaAs field-effect transistor (FET). IR light is absorbed in the detection layer and changes the surface potential of the transistor. The current in the transistor, which is very sensitive to those changes, should yield a sensitive detector. The same concept can be generalized to other adsorbents that absorb light at the various range of the spectrum. The advantage of using the mature technology of GaAs for achieving a low-cost efficient uncooled IR detector is clear. The experimental results presented here, using InAsSb as the absorbing layer, serve as a proof of the general concept