# Sub-Microsecond X-Ray Imaging Using Hole-Collecting Schottky type CdTe with Charge-Integrating Pixel Array Detectors

## TL;DR

This study demonstrates that hole-collecting Schottky type CdTe sensors can achieve sub-microsecond x-ray imaging, enabling time-resolved studies around 100 nanoseconds despite polarization effects.

## Contribution

The paper provides the first detailed analysis of the temporal response of hole-collecting Schottky CdTe sensors on nanosecond to second timescales.

## Key findings

- CdTe sensors show signal persistence up to hundreds of milliseconds due to shallow trap detrapping.
- Sub-microsecond response is achievable with proper bias and polarization management.
- Time resolution down to approximately 100 ns is possible with this sensor type.

## Abstract

CdTe is increasingly being used as the x-ray sensing material in imaging pixel array detectors for x-rays, generally above 20 keV, where silicon sensors become unacceptably transparent. Unfortunately CdTe suffers from polarization, which can alter the response of the material over time and with accumulated dose. Most prior studies used long integration times or CdTe that was not of the hole-collecting Schottky type. We investigated the temporal response of hole-collecting Schottky type CdTe sensors on timescales ranging from tens of nanoseconds to several seconds. We found that the material shows signal persistence on the timescale of hundreds of milliseconds attributed to the detrapping of a shallow trap, and additional persistence on sub-microsecond timescales after polarization. The results show that this type of CdTe can be used for time resolved studies down to approximately 100 ns. However quantitative interpretation of the signal requires careful attention to bias voltages, polarization and exposure history.