Development of 13 $\mu m$ Cutoff HgCdTe Detector Arrays for Astronomy

TL;DR

This paper reports on the development and testing of 13 μm cutoff HgCdTe detector arrays aimed at advancing infrared astronomy, demonstrating promising performance and paving the way for 15 μm detectors.

Contribution

The study presents the first successful testing of 13 μm HgCdTe detector arrays with reduced quantum tunneling dark current, advancing toward 15 μm detectors for astronomy.

Findings

Achieved at 28 K, a well depth of at least 75 ke^- for 90% of pixels.

Median dark current of 1.8 e^-/sec.

Demonstrated potential for longer wavelength detectors.

Abstract

Building on the successful development of the 10 $\mu m$ HgCdTe detector arrays for the proposed NEOCam mission, the University of Rochester Infrared Detector team and Teledyne Imaging Systems are working together to extend the cutoff wavelength of HgCdTe detector arrays initially to 13 $\mu m$, with the ultimate goal of developing 15 $\mu m$ HgCdTe detector arrays for space and ground-based astronomy. The advantage of HgCdTe detector arrays is that they can operate at higher temperatures than the currently used arsenic doped silicon detector arrays at the longer wavelengths. Our infrared detector team at the University of Rochester has received and tested four 13 $\mu m$ detector arrays from Teledyne Imaging Systems with three different pixel designs, two of which are meant to reduce quantum tunneling dark current. The pixel design of one of these arrays has mitigated the effects of quantum tunneling dark currents for which we have been able to achieve, at a temperature of 28 K and applied bias of 350 mV, a well depth of at least 75 $ke^-$ for 90% of the pixels with a median dark current of 1.8 $e^-/sec$. These arrays have demonstrated encouraging results as we move forward to extending the cutoff wavelength to 15 $\mu m$.