Performance Evaluation of Type-II Superlattice Devices Relative to HgCdTe Photodiodes

At present stage of infrared (IR) detector technology, two material systems, type-II superlattices (T2SLs) and HgCdTe ternary alloys, are used in fabrication of both mid- and long-wavelength IR arrays. The proposal of a new metric, the so-called “Law 19,” motivates the estimation of the potential performance of HgCdTe photodiodes compared to that of T2SL photodetectors. In these circumstances, the evaluation for assessing the merit of HgCdTe detectors relative to novel III–V devices with respect to performance may change. This work attempts to estimate the change in the performance of HgCdTe photodiodes relative to T2SL detectors. The main comparative efforts concern such photodiode parameters as dark currents and noise equivalent temperature differences.