Saman Salimpour - Department of Electrical Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran.
Hassan Rasooli Saghai - Department of Electrical Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran.

Infrared photo detectors have vast and promising applications in military,industrial and other fields. In this paper, we present a method for improving theperformance of an infrared photodetector based on an InSb substance. To achieve goodperformance at high temperatures, thermal noise and intrusive currents should bereduced. For this purpose, a five-layer hetero structure photodetector based on Weintroduce n+ InSb / n+ In۱-xAlxSb / π InSb / p+ In۱-xGaxSb / p+ InSb to improve thethermal performance in the mid-wavelength infrared (MWIR) range. With inserting oftwo thin layers from InAlSb and InGaSb on both side of the new (π) optical absorber created abarrier in the structure that prevents from entrance of diffusion currents and noise carriers at n+and p+ regions into the active area. And also by reducing the density of unwanted carriers in theactive layer, leads to decrease dark current, which is the main limiting factor for photodetectors’performance based on InSb. Our proposed design reduced ۴۹% dark current, increased۵۷% resistivity (R۰) and increased ۳۹% detectivity at ۳۰۰K. Simulation of the structurewas done using the SILVACO ATLAS software.

InSb Infrared Photodetector, High Temperature, Dark Current, Detectivity, Hetero Structure