Characterization of polycrystalline lead oxide for application in direct conversion X-ray detectors

Area of Science:

• Materials Science
• Solid-State Physics
• Detector Technology

Background:

• Polycrystalline lead oxide (poly-PbO) is a promising photoconductor for X-ray detection.
• Key performance parameters like charge yield and mobility-lifetime product (μτ) require further investigation.

Purpose of the Study:

• To investigate X-ray photogeneration and recombination processes in poly-PbO.
• To determine the energy required for electron-hole pair generation (W±) and the mobility-lifetime product (μτ).

Main Methods:

• Utilized X-ray induced photocurrent and pulse height spectroscopy.
• Applied the Hecht formula to analyze pulse height spectra.

Main Results:

• Energy required to release an electron-hole pair (W±) depends on the electric field, reaching ~20 eV/ehp at 10 V/μm.
• Mobility-lifetime products (μτ) for holes and electrons were determined to be 4.1 × 10⁻⁸ cm²/V and 10⁻⁹ cm²/V, respectively.
• Results suggest potential for improved PbO X-ray detector architectures.

Conclusions:

• Established W± and μτ values for poly-PbO under X-ray irradiation.
• Findings provide a basis for enhancing poly-PbO based X-ray detector performance.
• Proposed integration of Frisch grids or X-ray transistor architectures for technological advancement.