Max Bishop contributed to recently published work with STFC and the European Synchrotron Radiation Facility (ESRF), titled “Characterisation of the role of X-ray energy and temperature on the excess-leakage-current effect in HF-CdZnTe”.
As large science facilities move towards brighter and higher-energy X-ray beams, detector materials are needed that can perform reliably under these more demanding conditions. High-flux capable Cadmium Zinc Telluride (HF-CdZnTe) is a promising candidate, but previous work has identified an increase in leakage current under irradiation which could affect detector performance.
In this study, measurements carried out at the BM05 beamline of the ESRF were used to investigate what causes this effect and how it changes with time and temperature. The results showed that the excess leakage current increases more strongly with photon energy than flux alone would predict, linked to increased charge trapping as higher-energy X-rays interact deeper within the detector material. By varying the temperature, and analysing the ‘afterglow’ from the sensor after the X-rays are turned off, the paper explores the multiple processes contributing to the excess leakage current.
Building a clearer picture of how the excess leakage current arises helps us better understand how HF-CdZnTe behaves under intense X-ray irradiation, supporting the design of detectors for brighter, high-energy X-ray sources