Optical EngineeringInfrared photodetector with electromagnetic carrier depletion
|Format||Member Price||Non-Member Price|
A method is presented for thermal noise reduction in a near room-temperature intrinsic IR photodetector. The method is based on suppression of the Auger generation-recombination processes using the electro-magnetic carrier depletion (EMCD) of a narrow gap semiconductor. The device is a lightly doped narrow gap semiconductor flake with a high backside surface recombination velocity, supplied with electrical contact band and placed in a magnetic field. Due to the action of the Lorentz force most of the device depletes charge carriers, which results in suppression of the Auger generation and recombination processes. As a result, the I-V characteristic becomes nonlinear, exhibiting regions of high positive and negative resistance. Thermal noise can be dramatically reduced, leading to a substantial improvement in performance. The ultimate detection may be determined either by background radiation or by Shockley-Read generation, depending on the ratio of the background photon flux to the recombination center concentration. Near-BLIP performance is predicted for 10.6-μm (Hg, Cd) Te devices, prepared from high-quality materials and operated at 225-250 K.