Overview of GaAs und CdTe Pixel Detectors Using Medipix Electronics

Fiederle, M.; Procz, S.; Hamann, Elias; Fauler, A.; Fröjdh, Christer

doi:10.1002/crat.202000021

Cited by 22 publications

(12 citation statements)

References 29 publications

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“…For a semiconductor to serve as an X-ray detector with characteristics approaching ideal performance, several requirements must be fulfilled: high resistivity (≤10 10 Ω cm) and hence sufficiently low noise levels for resolving charges generated by a single photon, high carrier mobility-lifetime (µτ) product for the efficient collection of photon-generated carriers, and absorption of (nearly) all X-ray photons-the latter scales with the thickness and the average atomic number (Z) of constituting elements. Very few high-Z semiconductors were proposed to fulfill these requirements at room temperature 6,14,15,16,17 and thus far, only costly, ultrapure CdTe and CdZnTe single crystals, usually grown from a melt by high-pressure Bridgman or by Czochralski methods, have been commercially deployed 18,19 . Lead halide perovskite semiconductors (general formula APbX3, where A is a cation, either organic methylammonium (MA + ) or formamidinium, or inorganic Cs + ; and X is an anion of I, Br or Cl halogen) are the most intensely studied class of contender high-Z materials for high-energy photon detection 3,4,5,6,7,12,13,20,21,22,23,24,25,26,27,28 .…”

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confidence: 99%

Stable near-to-ideal performance of a solution-grown single-crystal perovskite X-ray detector

Kovalenko

Sakhatskyi

Türedi

et al. 2021

Preprint

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The ideal photodetector is the one able to detect every single incoming photon. In particular, in X-ray medical imaging, the radiation dose for patients can then approach its fundamentally lowest limit set by the Poisson photon statistics. Such near-to-ideal X-ray detection characteristics have been demonstrated with only a few semiconductor materials such as Si1 and CdTe2; however, their industrial deployment in medical diagnostics is still impeded by elaborate and costly fabrication processes. Hybrid metal halide perovskites – newcomer semiconductors -– make for a viable alternative3,4,5 owing to their scalable, inexpensive, robust, and versatile solution growth and recent demonstrations of single gamma-photon counting under high applied bias voltages6,7. The major hurdle with perovskites as mixed electronic-ionic conductors, however, arises from the rapid material's degradation under high electric field8,9,10,11, thus far used in perovskite X-ray detectors12,13. Here we show that both near-to-ideal and long-term stable performance of perovskite X-ray detectors can be attained in the photovoltaic mode of operation at zero-voltage bias, employing thick and uniform methylammonium lead iodide (MAPbI3) single crystal (SC) films (up to 300 µm), solution-grown directly on hole-transporting electrodes. The operational device stability is equivalent to the intrinsic chemical shelf lifetime of MAPbI3, being at least one year in the studied case. Detection efficiency of 88% and noise equivalent dose of 90 pGyair (lower than the dose of a single incident photon) are obtained with 18 keV X-rays, allowing for single-photon counting, as well as low-dose and energy-resolved X-ray imaging. These findings benchmark hybrid perovskites as practically suited materials for developing low-cost commercial detector arrays for X-ray imaging technologies.

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confidence: 99%

Stable near-to-ideal performance of a solution-grown single-crystal perovskite X-ray detector

Kovalenko

Sakhatskyi

Türedi

et al. 2021

Preprint

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“…In parallel, a lot of effort is currently being invested in direct detectors based on high-Z materials, e.g. based on AsGa and CdTe (Pennicard et al, 2018;Brombal et al, 2018;Fiederle et al, 2020). However, the decisive advantage of indirect detectors is to offer a very uniform and easily scalable field of view at a reasonable cost.…”

Section: Discussionmentioning

confidence: 99%

Indirect X-ray detectors with single-photon sensitivity

Pauwels

Douissard

2022

J Synchrotron Radiat

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The new generation of synchrotron light sources are pushing X-ray detectors to their limits. Very demanding conditions with unprecedented flux and higher operating energies now require high-performance X-ray detectors combining sensitivity, efficiency and scalability. Over the years, hybrid pixel detectors have supplemented indirect detectors based on scintillation, with undeniable advantages. Such detectors based on silicon are, however, rather expensive to produce and are no more satisfying in terms of X-ray stopping power when targeting energies above 20 keV. An indirect detector with single X-ray photon sensitivity therefore offers promising opportunities for applications operating over a wide range of energies and fluxes. In this work, the performances of such an approach are investigated with state-of-the-art elements: a commercial sCMOS camera with fiber-optics plate coupling and a Gd2O2S:Tb powder-based scintillator. A simple method is presented for evaluation of the single X-ray photon detection limit and single X-ray sensitivity is demonstrated with the studied detector above 20 keV. Geant4 simulations also provide insight to better define the limiting factors. Finally, guidelines are provided for future R&D in the design and assembly of an innovative detector combining advantages of direct and indirect detection schemes.

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“…The minimum threshold limit depends on the type and thickness of the used detection layer material and the internal noise of the ASIC chip. Typical detection layers can be Silicon (Si), Cadmium Telluride (CdTe), or Gallium Arsenide (GaAs) in various thicknesses [ 31 , 32 ]. For the Si detection layer, which was used in the presented work, the minimum threshold value is as low as 2 keV [ 33 ].…”

Section: Methodsmentioning

confidence: 99%

Timepix3: Compensation of Thermal Distortion of Energy Measurement

Urban

Nentvich

Marek

et al. 2023

Sensors

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The Timepix3 is a hybrid pixellated radiation detector consisting of a 256 px × 256 px radiation-sensitive matrix. Research has shown that it is susceptible to energy spectrum distortion due to temperature variations. This can lead to a relative measurement error of up to 35% in the tested temperature range of 10 °C to 70 °C. To overcome this issue, this study proposes a complex compensation method to reduce the error to less than 1%. The compensation method was tested with different radiation sources, focusing on energy peaks up to 100 keV. The results of the study showed that a general model for temperature distortion compensation could be established, where the error in the X-ray fluorescence spectrum of Lead (74.97 keV) was reduced from 22% to less than 2% for 60 °C after the correction was applied. The validity of the model was also verified at temperatures below 0 °C, where the relative measurement error for the Tin peak (25.27 keV) was reduced from 11.4% to 2.1% at −40 °C. The results of this study demonstrate the effectiveness of the proposed compensation method and models in significantly improving the accuracy of energy measurements. This has implications for various fields of research and industry that require accurate radiation energy measurements and cannot afford to use power for cooling or temperature stabilisation of the detector.

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Overview of GaAs und CdTe Pixel Detectors Using Medipix Electronics

Cited by 22 publications

References 29 publications

Stable near-to-ideal performance of a solution-grown single-crystal perovskite X-ray detector

Stable near-to-ideal performance of a solution-grown single-crystal perovskite X-ray detector

Indirect X-ray detectors with single-photon sensitivity

Timepix3: Compensation of Thermal Distortion of Energy Measurement

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