Cadmium Zinc Telluride Detector Materials and Performance

Cadmium zinc telluride (CdZnTe) has emerged as the leading room-temperature semiconductor for X- and γ-ray detection, owing to its wide band gap, high atomic number and excellent electron charge transport properties. Intrinsic challenges such as compositional inhomogeneity due to zinc segregation, networks of sub-grain boundaries and sub-micrometre tellurium inclusions, however, limit the yield of detector-grade material and degrade spectral response. The advent of quaternary alloys, notably cadmium zinc telluride selenide (CdZnTeSe or CZTS), has addressed many of these issues by enhancing stoichiometric uniformity and suppressing defect networks. Advances in crystal growth methods—especially the traveling heater method and refined Bridgman techniques—have yielded large-volume ingots with high compositional homogeneity. Detectors incorporating virtual Frisch grid designs now routinely achieve energy resolutions approaching 1% at 662 keV, making them ideally suited to medical imaging, homeland security, non-proliferation and high-energy physics. Current efforts centre on further reducing residual impurities and optimising hole transport to advance sensitivity and resolution.

Research from Nature Portfolio

Recent studies have demonstrated that selenium incorporation into the CdZnTe matrix substantially elevates detector performance. Initial work on Cd_0.9Zn_0.1Te_0.98Se_0.02 grown by the traveling heater method produced virtual Frisch grid detectors with energy resolutions between 0.9% and 1.5% at 662 keV, attributed to exceptionally low defect densities and uniform composition. Building on this, optimisation of growth parameters achieved a record resolution of 0.77% at 662 keV without post-processing corrections, alongside the complete elimination of sub-grain boundaries and thermal stress as confirmed by X-ray topography and infrared transmission imaging. Foundational research has also shown that even minimal selenium addition effectively suppresses zinc segregation, sub-grain boundary networks and tellurium precipitates, thereby increasing the yield of high-performance quaternary crystals suited to large-volume detector production.

Cadmium Zinc Telluride Detector Materials and Performance publication trend

The graph below shows the total number of articles in cadmium zinc telluride detector materials and performance across all publications each year (not limited to Nature Index journals).

Technical terms

Virtual Frisch grid: Electrode architecture that decouples charge collection from carrier trapping to boost spectral resolution.

Energy resolution: Full width at half maximum of a spectral peak, indicating a detector’s ability to distinguish photon energies.

Electron mobility-lifetime product (µτ): Parameter quantifying the average distance charge carriers travel before recombination or trapping.

Compositional homogeneity: Uniform distribution of constituent elements within a crystal lattice, critical for consistent detector response.

Sub-grain boundary: Low-angle crystallographic interface where slight misorientation between adjacent regions can trap carriers.

Tellurium inclusions: Microscopic precipitates of elemental tellurium that act as deep traps, degrading charge transport and resolution.

Traveling Heater Method: Crystal growth technique employing a moving thermal gradient to produce high-purity semiconductor ingots.

References

1. Evaluation of CdZnTeSe as a high-quality gamma-ray spectroscopic material with better compositional homogeneity and reduced defects. Scientific Reports (2019).
2. Role of selenium addition to CdZnTe matrix for room-temperature radiation detector applications. Scientific Reports (2019).
3. Impact of selenium addition to the cadmium-zinc-telluride matrix for producing high energy resolution X-and gamma-ray detectors. Scientific Reports (2021).
4. Advances in CdZnTeSe for Radiation Detector Applications. Radiation (2021).
5. Optimizing CdZnTeSe Frisch-Grid Nuclear Detector for Gamma-Ray Spectroscopy. IEEE Access (2020).