Cold performance tests of blocked-impurity-band Si:As detectors developed for DARWIN

TL;DR

This paper presents initial laboratory test results of Si:As blocked-impurity-band detectors designed for mid-infrared space missions, focusing on their spectral response, efficiency, dark current, and radiation effects.

Contribution

It introduces new Si:As BIB detector prototypes with integrated cryogenic readout electronics and provides comprehensive characterization data for their performance.

Findings

Spectral response and quantum efficiency characterized

Dark current and temperature dependence measured

Radiation effects on detectors studied

Abstract

We report first results of laboratory tests of Si:As blocked-impurity-band (BIB) mid-infrared (4 to 28 um) detectors developed by IMEC. These prototypes feature 88 pixels hybridized on an integrated cryogenic readout electronics (CRE). They were developed as part of a technology demonstration program for the future DARWIN mission. In order to be able to separate detector and readout effects, a custom build TIA circuitry was used to characterize additional single pixel detectors. We used a newly designed test setup at the MPIA to determine the relative spectral response, the quantum efficiency, and the dark current. All these properties were measured as a function of operating temperature and detector bias. In addition the effects of ionizing radiation on the detector were studied. For determining the relative spectral response we used a dual-grating monochromator and a bolometer with known response that was operated in parallel to the Si:As detectors. The quantum efficiency was measured by using a custom-build high-precision vacuum black body together with cold (T ~ 4 K) filters of known (measured) transmission.