Signal generation in CdTe X-ray sensors

TL;DR

This paper explains the detailed signal generation mechanism in CdTe semiconductor X-ray sensors, focusing on Schottky-type CdTe:Cl sensors used in ESA's Solar Orbiter mission, with derivations based on fundamental semiconductor principles.

Contribution

It provides a comprehensive derivation of the signal generation process in CdTe sensors, applicable to various semiconductors, with specific focus on sensors used in space-based X-ray instruments.

Findings

Derivation of signal generation equations for CdTe sensors

Application of analysis to Schottky-type CdTe:Cl sensors

Relevance to space-based X-ray detection instruments

Abstract

This write-up explains the signal generation mechanism in CdTe semiconductor sensors. Derivations are mostly carried out explicitly, starting with basic semiconductor relations. The analysis is largely applicable to any semiconductor, with the focus being on the Schottky-type CdTe:Cl sensors that are employed in the Spectrometer/Telescope for Imaging X-rays (STIX) instrument on-board the ESA Solar Orbiter mission.