High operating temperature MWIR detectors

Abstract

The High Operating Temperature Auger suppressed infrared detector concept is being pursued using the high density vertically integrated photodiode (HDVIP ® ) architecture and an n + -p device structure. Dark current densities as low as 2.5 mA/cm 2 normalized to a 5 µm cutoff at 250K have been demonstrated on these diodes. These dark currents imply minority carrier lifetimes in excess of 300µsec. 1/f noise in these devices arises from the tunneling of charge into the passivation interface, giving rise to a modulation in the surface positive charge and hence to the width of the depletion region in the p-side of the device and a modulation in the total dark current. The measured 1/f noise is in agreement with the predictions of this model, with very low noise being observed when the lifetimes are high.

Broadband Infrared Heterodyne Spectrometer: Final Report

“…The conventional VIGO detector [11] has a frequency roll-off at ~ 1 GHz. The DRS HOT detector [1] and the Qinetic (nBn) detector [2] have intrinsically low frequency response and are shown for comparison.…”

“…Estimates of the possible reduction in power requirements have been made and the pay-off can be substantial. One such estimate [1] is presented in Figure 1.…”

Numerical Modeling of SRH and Tunneling Mechanisms in High-Operating-Temperature MWIR HgCdTe Photodetectors

“…Since HOT infrared detectors should preserve at 150 K and above the performance characteristics formerly obtained at substantially lower temperatures (80 K to 100 K), a considerable reduction of the dark current is essential to obtain high sensitivity. [8][9][10][11] Two sets of devices, manufactured with the same nominal structure but different p-doping technologies, are presented in ''Device Fabrication and Experimental Dark Currents'' section, and their experimental dark currents are compared and discussed. In ''Simulation of the Low Reverse Bias Regime'' section, a simulation study of the dark currents demonstrates the favorable effects on Shockley-Read-Hall (SRH) and Auger generationrecombination (GR) rates of avoiding metal-vacancy doping and reducing the acceptor density.…”