High signal-to-noise ratio HgI<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="d1e104" altimg="si1.svg"><mml:msub><mml:mrow/><mml:mrow><mml:mi mathvariant="bold">2</mml:mi></mml:mrow></mml:msub></mml:math> X-ray detector assisted with ultraviolet radiation

Lee, Dong‐Wook; Lee, Kang-Ho; Seo, Jiwon

doi:10.1016/j.nima.2019.162364

Cited by 7 publications

(3 citation statements)

References 24 publications

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“…Currently, the direct conversion of X-ray to electrical signal of commercial detectors is mainly based on amorphous selenium (α-Se) and cadmium zinc telluride (CZT). Other materials with high atomic numbers have also shown great potential for X-ray detection and imaging, such as CdTe, − lead oxide, polycrystalline HgI 2 , − and metal halide perovskites. − However, most of the current X-ray detection materials are still suffering from the poor stability, particularly under intense ionizing irradiation. It could be mainly due to the high attenuation coefficient of these dense materials with “heavy” atoms, and the incident high energy photons could be easily intercepted and have a great potential to generate large density of defects .…”

Section: Introductionmentioning

confidence: 99%

Neutron Irradiation Effects on Boron Nitride-Based Ceramics for Use in X-ray Detection

Chen

Yang

Yao

et al. 2023

ACS Appl. Mater. Interfaces

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X-ray detectors based on conventional semiconductors with large atomic numbers are suffering from the poor stability under a high dose rate of ionizing irradiation. In this work, we demonstrate that a wide band gap ceramic–boron nitride with small atomic numbers could be used for sensitive X-ray detection. Boron nitride samples showed excellent resistance to ionizing radiation, which have been systematically studied with the neutron- and electron-aging experiments. Then, we fully analyzed the influence of these aging effects on the fundamental properties of boron nitride. Interestingly, we found that the boron nitride samples could maintain relatively good charge transport properties even after large dose of neutron irradiation. The fabricated X-ray detectors showed decent performance metrics, and the neutron-aged boron nitride even showed improved operational stability under continuous X-ray irradiation, suggesting the great potential for real applications.

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Section: Introductionmentioning

confidence: 99%

Neutron Irradiation Effects on Boron Nitride-Based Ceramics for Use in X-ray Detection

Chen

Yang

Yao

et al. 2023

ACS Appl. Mater. Interfaces

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“…The requirement for a relatively low deposition temperature makes single-crystalline photoconductors unsuitable for use in direct conversion imaging detectors. As for the disordered (polycrystalline and amorphous), high-Z semiconductors that can produce large-area detectors, polycrystalline layers of PbI 2 [8][9][10], HgI 2 [10][11][12], CdTe [13], Cd 1-x Zn x Te [14], BiI 3 [15], ZnO [16], PbO [17,18], perovskites [19], and amorphous PbO (a-PbO) [20,21] are considered promising. However, at the current stage of their technology, the majority of the materials in this list exhibit signal lag-a residual current that continues to flow after X-ray exposure [17,18,22].…”

Section: Introductionmentioning

confidence: 99%

The X-ray Sensitivity of an Amorphous Lead Oxide Photoconductor

Grynko

Thibault

Pineau

et al. 2021

Sensors

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The photoconductor layer is an important component of direct conversion flat panel X-ray imagers (FPXI); thus, it should be carefully selected to meet the requirements for the X-ray imaging detector, and its properties should be clearly understood to develop the most optimal detector design. Currently, amorphous selenium (a-Se) is the only photoconductor utilized in commercial direct conversion FPXIs for low-energy mammographic imaging, but it is not practically feasible for higher-energy diagnostic imaging. Amorphous lead oxide (a-PbO) photoconductor is considered as a replacement to a-Se in radiography, fluoroscopy, and tomosynthesis applications. In this work, we investigated the X-ray sensitivity of a-PbO, one of the most important parameters for X-ray photoconductors, and examined the underlying mechanisms responsible for charge generation and recombination. The X-ray sensitivity in terms of electron–hole pair creation energy, W±, was measured in a range of electric fields, X-ray energies, and exposure levels. W± decreases with the electric field and X-ray energy, saturating at 18–31 eV/ehp, depending on the energy of X-rays, but increases with the exposure rate. The peculiar dependencies of W± on these parameters lead to a conclusion that, at electric fields relevant to detector operation (~10 V/μm), the columnar recombination and the bulk recombination mechanisms interplay in the a-PbO photoconductor.

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“…Thus, it is imperative to focus on amorphous and polycrystalline phases of high- Z photoconductors, that can be directly deposited on an imaging array of a large area. Potential X-ray photoconductors such as polycrystalline layers of BiI 3 2 , PbI 2 3 , 4 , HgI 2 5 – 7 , ZnO 8 , CdTe 9 , Cd 1−x Zn x Te 10 , and PbO 11 have been investigated and have shown potential for use in direct conversion detectors. The X- ray-to-charge conversion rate of these materials is 3–8 times larger than that of a-Se and thus, they are capable of X-ray quantum noise limited operation at low exposures, since the X-ray quantum noise can prevail over the electronic noise.…”

Section: Introductionmentioning

confidence: 99%

Bilayer lead oxide X-ray photoconductor for lag-free operation

Grynko

Thibault

Pineau

et al. 2020

Sci Rep

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Polycrystalline Lead Oxide (poly-PbO) was considered one of the most promising photoconductors for the direct conversion X-ray medical imaging detectors due to its previous success in optical imaging, i.e., as an optical target in so-called Plumbicon video pick-up tubes. However, a signal lag which accompanies X-ray excitation, makes poly-PbO inapplicable as an X-ray-to-charge transducer in real-time X-ray imaging. In contrast, the recently synthesized Amorphous Lead Oxide (a-PbO) photoconductor is essentially lag-free. Here, we report on our approach to a PbO detector where a thin layer of a-PbO is combined with a thick layer of poly-PbO for lag-free operation. In the presented a-PbO/poly-PbO bilayer structure, the poly-PbO layer serves as an X-ray-to-charge transducer while the a-PbO acts as a lag prevention layer. The hole mobility in the a-PbO/poly-PbO bilayer structure was measured by photo-Charge Extraction by Linearly Increasing Voltage technique at different temperatures and electric fields to investigate charge transport properties. It was found that the hole mobility is similar to that in a-Se—currently the only commercially viable photoconductor for the direct conversion X-ray detectors. Evaluation of the X-ray temporal performance demonstrated complete suppression of signal lag, allowing operation of the a-PbO/poly-PbO detector in real-time imaging.

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High signal-to-noise ratio HgI2 X-ray detector assisted with ultraviolet radiation

Cited by 7 publications

References 24 publications

Neutron Irradiation Effects on Boron Nitride-Based Ceramics for Use in X-ray Detection

Neutron Irradiation Effects on Boron Nitride-Based Ceramics for Use in X-ray Detection

The X-ray Sensitivity of an Amorphous Lead Oxide Photoconductor

Bilayer lead oxide X-ray photoconductor for lag-free operation

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