Design of an Auger-Suppressed Unipolar HgCdTe NBνN Photodetector

A unipolar mercury cadmium telluride (HgCdTe) NB nu N infrared (IR) device architecture is analyzed by physics-based numerical device simulations. The device structure is predicted to suppress Shockley-Read-Hall (SRH) and Auger generation-recombination (G-R) processes, while also providing a simplified fabrication process by eliminating p-type doping requirements. The performance characteristics of mid- and long-wavelength infrared (MWIR: lambda (c) = 5 mu m; LWIR: lambda (c) = 12 mu m) NB nu N devices are calculated and compared with those of nBn and double-layer planar heterostructure (DLPH) devices. Theoretical dark current density (J (dark)) values of the MWIR and LWIR NB nu N devices are lower by an order of magnitude or more for temperatures between 50 K and 225 K. Calculated peak detectivity (D (*)) values of 6.01 x 10(14) cm Hz(0.5)/W to 2.36 x 10(10) cm Hz(0.5)/W for temperatures from 95 K to 225 K, and 2.37 x 10(14) cm Hz(0.5)/W to 2.27 x 10(11) cm Hz(0.5)/W for temperatures from 50 K to 95 K are observed for MWIR and LWIR NB nu N structures, respectively. A component of the NB nu N structure, embodied in a unipolar MWIR nBn device, is also fabricated to experimentally demonstrate selective carrier extraction.