Research on dark current characteristics of InAsSb Barrierblocking infrared detector

The carrier lifetimes determined by radiative and Auger 1 recombination in InAs 1-xSb x were calculated at different temperatures. For n-type InAsSb material,at low temperatures,the carrier lifetime is limited by the radiative recombination,while at high temperatures,the Auger 1 process is dominant. An analytical model of dark current for barrier blocking detectors was discussed,by adding a heavily doped n-type InAsSb electrode on the other side of the absorber layer to form an nBnn(+) structure to deplete the carriers in absorber,the hole concentration in absorption region was decreased about two orders of magnitude,further reducing the dark current of the devices. InAsSb-based nBnn(+) barrier devices have been successfully fabricated and characterized. At 150 K,the devices displayed a dark current density as low as 3x10(-6) A/cm(2),the dark current density of the detectors was fitted by the nBn-based architecture analytical current model,the experimental results indicated that due to the p-type doping of the barrier layer,a depletion region was formed in the InAsSb absorber region,resulting in incomplete inhibition of G-R current. At temperatures below 180 K,the dark current of the detector is limited by G-R process,at temperatures above 180 K,the dark current of the device is limited by diffusion current.