Temperature Dependence of Dark Signal for Sentinel-4 Detector

The Sentinel-4 payload is a multi-spectral camera system which is designed to monitor atmospheric conditions over Europe. The German Aerospace Center (DLR) in Berlin, Germany conducted the verification campaign of the Focal Plane Subsystem (FPS) on behalf of Airbus Defense and Space GmbH, Ottobrunn, Germany. In this publication, we will present in detail the temperature dependence of dark signal for the CCD 376 (NIR) from e2v. Dark current is strongly temperature-dependent and is based on the thermal excitation of electrons in the conduction band. During the testing the temperature of the detectors was varied between 215K and 290K. Different models were examined, and corresponding deviations determined. Presenting the dark current by means of an Arrhenius plot, it can be shown, that the activation energy is about half of the band gap. As an important result it could be shown that the temperature dependence can be described by two activation energies.