Electric-Field Mapping of Optically Perturbed CdTe Radiation Detectors

Area of Science:

• Materials Science
• Solid-State Physics
• Detector Physics

Background:

• The electric field distribution is critical for radiation detector operation.
• Internal space charge accumulation can impair detector function.
• Understanding electric field dynamics is key to improving detector performance.

Purpose of the Study:

• To investigate the two-dimensional electric field in a Schottky CdTe detector.
• To analyze electric field perturbations caused by optical beam exposure.
• To validate a model explaining field dynamics and detector polarization.

Main Methods:

• Utilized the Pockels effect for electro-optical imaging of the electric field.
• Developed a custom processing routine for electric-field vector map extraction.
• Performed voltage bias and optical exposure sequences on the CdTe detector.

Main Results:

• Successfully mapped the local perturbation of the electric field at the anode electrode.
• Observed the dynamics of the electric field during voltage bias and optical exposure.
• Results align with numerical simulations, confirming a two-level deep level model.

Conclusions:

• The two-level model accurately describes the temporal and spatial dynamics of the perturbed electric field.
• This approach enhances understanding of non-equilibrium electric fields in CdTe Schottky detectors.
• The method can predict and improve performance for future detector designs.