High performance platinum contacts on high-flux CdZnTe detectors.

Area of Science:

• Materials Science
• Semiconductor Physics
• X-ray Detection Technology

Background:

• The demand for high-flux X-ray detectors has surged with 4th Generation Synchrotron Light Sources and advanced medical/industrial imaging.
• Standard Cadmium Zinc Telluride (CZT) detectors (LF-CZT) suffer from polarization effects and high dark currents under high photon flux.
• Novel Cadmium Zinc Telluride (CZT) materials (HF-CZT) offer improved hole transport but require optimized electrical contacts.

Purpose of the Study:

• To investigate and characterize new sputtered platinum electrical contacts for high-flux Cadmium Zinc Telluride (HF-CZT) detectors.
• To address the issue of high dark leakage currents observed with standard contacts on HF-CZT devices.
• To evaluate the performance enhancement of HF-CZT detectors using optimized platinum contacts.

Main Methods:

• Fabrication and testing of HF-CZT detectors with sputtered platinum anode and cathode contacts.
• Electrical and spectroscopic investigations to assess detector performance.
• Transmission Electron Microscopy (TEM) and Focused Ion Beam (FIB) analysis of the platinum/CZT interface.

Main Results:

• Optimized sputtered platinum contacts demonstrated superior performance on HF-CZT detectors.
• Platinum anode coupled with platinum or gold cathode yielded the best results, significantly reducing dark leakage currents.
• TEM/FIB analysis revealed the presence of CdTeO3 oxide at the Pt/CZT interface, providing insights into contact behavior.

Conclusions:

• Sputtered platinum contacts are effective in mitigating dark leakage currents in HF-CZT detectors.
• Optimized Pt/CZT contacts enhance detector suitability for high-flux X-ray applications.
• Understanding the interface chemistry is crucial for further development of high-performance X-ray detectors.