Theoretical Study of Quaternary nBp InGaAsSb SWIR Detectors for Room Temperature Condition

This paper presents a theoretical analysis of an nBp infrared barrier detector's performance intended to operate at a room temperature (300 K) based on A^IIIB^V materials-In_1-<i>x</i>Ga<i>_x</i>As_ySb_1-<i>y</i> quaternary compound-lattice-matched to the GaSb substrate with a p-n heterojunction ternary Al_1-<i>x</i>Ga<i>_x</i>Sb barrier. Numerical simulations were performed using a commercial Crosslight Software-package APSYS. The band structure of the nBp detector and the electric field distribution for the p-n heterojunction with and without a potential barrier were determined. The influence of the barrier-doping level on the detector parameters was analyzed. It was shown that Shockley-Read-Hall (SRH) recombination plays a decisive role in carrier transport for lifetimes shorter than 100 ns. The influence of the absorber/barrier thickness on the detector's dark current density and photocurrent was investigated. It was shown that valence band offset does not influence the device's performance. The quantum efficiency reaches its maximum value for an absorber's thickness of ~3 μm. The performed simulations confirmed the possibility of the detector's fabrication exhibiting high performance at room temperature based on quaternary compounds of A^IIIB^V materials for the short wavelength infrared range.