Core Application Fields and Technical Value of Cadmium Zinc Telluride (CdZnTe)

Core Application Fields and Technical Value of Cadmium Zinc Telluride (CdZnTe)

I. Medical Imaging and Diagnostics

1. Nuclear Medicine Imaging Devices

   • As the core material for gamma cameras, SPECT (Single-Photon Emission Computed Tomography), and PET (Positron Emission Tomography), CdZnTe leverages its high energy resolution (FWHM <4% at 140 keV) and direct photon-counting capability to enable low-dose, high-contrast imaging of lesions (e.g., tumor localization, cardiac function assessment).
   • Case: In photon-counting spectral CT, CdZnTe detectors achieve 15–20% energy resolution in the 80–140 keV range, supporting "color CT" for precise tissue composition differentiation.

2. X-ray Diagnostic Equipment

   • Used in mammography, bone densitometry (DXA), etc., directly converting X-rays to electrical signals to reduce radiation dose while enhancing image details (e.g., early detection of osteoporosis microstructures).

II. Nuclear Security and Radiation Monitoring

1. Radioactive Material Detection

   • Portable gamma-ray spectrometers with CdZnTe's room-temperature detection capability rapidly identify nuclear materials like uranium or plutonium (e.g., border security, nuclear power plant leak response), with detection sensitivity reaching the nanocurie level.
   • Fixed monitoring systems for environmental radiation background measurement and isotope analysis in nuclear waste treatment.

2. Industrial Non-Destructive Testing

   • In aerospace and pipeline inspection, CdZnTe detectors use X-ray/gamma-ray imaging to identify internal material defects (e.g., welding cracks, pipeline corrosion), supporting high-throughput detection (millions of photons/mm² per second).

III. Infrared Detection and Optoelectronics

1. Infrared Detector Substrates

   • As an epitaxial substrate for HgCdTe (mercury cadmium telluride) infrared focal plane arrays, CdZnTe enables high-performance mid-to-long-wave infrared detectors via lattice matching (lattice mismatch <0.1% with HgCdTe), applied in:
     • Military night vision and missile guidance systems;
     • Industrial thermal imaging (e.g., power equipment fault warning);
     • Astronomical infrared observation (e.g., exoplanet detection).

2. UV-Visible Light Detectors

   • Based on CdZnTe's wide bandgap (1.4–1.6 eV), solar-blind UV detectors are developed for flame monitoring, high-voltage corona discharge detection, etc.

IV. Astrophysics and Space Science

1. X-ray/Gamma-ray Astronomical Observations

   • Deployed on satellites (e.g., future gamma-ray observatories), detecting high-energy cosmic objects (supernova remnants, black hole accretion disks) and distinguishing radiation sources via energy resolution (e.g., 10–100 keV X-ray bursts).
   • Advantage: No cryogenic cooling needed, reducing spacecraft payload—suitable for deep-space exploration (e.g., Mars radiation environment monitoring).

2. Particle Physics Experiments

   • In high-energy particle collider experiments (e.g., future circular colliders), serving as track detectors and energy counters to capture secondary particles from proton-proton collisions, supporting research on new physical phenomena (e.g., indirect dark matter detection).

V. Industrial and Research Frontiers

1. Material Analysis and Characterization

   • X-ray fluorescence spectroscopy (XRF) analyzers use CdZnTe's high energy resolution to precisely determine material composition (e.g., semiconductor wafer impurity analysis, archaeological artifact composition identification).

2. Quantum Technology and Radiation Metrology

   • As standard radiation detectors for calibrating gamma-ray source intensity (e.g., medical radiotherapy dose calibration);
   • Exploring integration of quantum dot infrared photodetectors (QDIP) with CdZnTe to advance quantum communication and sensing.

VI. Strategic and Defense Applications

1. Nuclear Deterrence and Missile Defense

   • In ground/space-based nuclear explosion monitoring networks, CdZnTe detectors track gamma-ray spectra from nuclear explosions in real time, supporting nuclear treaty verification and global strategic warning.

2. Military Imaging and Reconnaissance

   • Man-portable infrared imagers and UAV-mounted multispectral detectors use CdZnTe-HgCdTe composite technology to enhance night vision range and anti-jamming capability.

VII. Technical Challenges and Trends

• Bottlenecks: Zn segregation and lattice defect control in large-size single crystal growth (e.g., diameter >100 mm), keeping detector costs high.
• Frontier Directions:
  • Heteroepitaxy (growing CdZnTe films on Si/Ge substrates) to reduce costs;
  • Integration of AI with CdZnTe detectors to optimize radiation imaging algorithms (e.g., dynamic noise reduction, real-time 3D reconstruction).

Conclusion

With unique advantages of "room-temperature detection + high energy resolution + broad spectral response," CdZnTe serves as a strategic material in medicine, nuclear security, aerospace, and other fields. Its application expansion relies not only on breakthroughs in material preparation but also drives interdisciplinary technological innovation—from disease diagnosis to cosmic exploration.