Characterization of photon counting pixel detectors based on semi-insulating GaAs sensor material

Hamann, Elias; Cecilia, A.; Zwerger, A.; Fauler, A.; Толбанов, О. П.; Tyazhev, A.; Shelkov, G.A.; Graafsma, H.; Baumbach, Tilo; Fiederle, M.

doi:10.1088/1742-6596/425/6/062015

Cited by 23 publications

(31 citation statements)

References 9 publications

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“…The resistivity was measured to be cm in the linear range, which is in agreement with previous measurements carried out using the same batch of material [23].…”

Section: A Detector Characterizationsupporting

confidence: 89%

“…This technique previously demonstrated to provide sensors with resistivities in the order of cm [23], [28], [29] via high compensation rates. Due to the high dopant concentration, the width of the space charge regions (SCR) behind the metal (Schottky) contacts are small, leading to the bias voltage dropping mainly across the sensor and thus to a uniform distribution of the electric field [21], [24], [30].…”

Section: Detector Fabrication and Chip Descriptionmentioning

confidence: 99%

“…It is based on the compensation of GaAs wafers by chromium (Cr) diffusion and has shown to provide fully active, high resistivity (HR) sensors with thicknesses up to 1 mm [21]. As was demonstrated recently [23], [24], these HR-GaAs:Cr sensors exhibit detector-grade material properties and, in combination with photon counting Timepix readout chips, provide an excellent image quality.…”

Section: Introductionmentioning

confidence: 99%

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Performance of a Medipix3RX Spectroscopic Pixel Detector With a High Resistivity Gallium Arsenide Sensor

Hamann

Koenig

Zubér

et al. 2015

IEEE Trans. Med. Imaging

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High resistivity gallium arsenide is considered a suitable sensor material for spectroscopic X-ray imaging detectors. These sensors typically have thicknesses between a few hundred μm and 1 mm to ensure a high photon detection efficiency. However, for small pixel sizes down to several tens of μm, an effect called charge sharing reduces a detector's spectroscopic performance. The recently developed Medipix3RX readout chip overcomes this limitation by implementing a charge summing circuit, which allows the reconstruction of the full energy information of a photon interaction in a single pixel. In this work, we present the characterization of the first Medipix3RX detector assembly with a 500 μm thick high resistivity, chromium compensated gallium arsenide sensor. We analyze its properties and demonstrate the functionality of the charge summing mode by means of energy response functions recorded at a synchrotron. Furthermore, the imaging properties of the detector, in terms of its modulation transfer functions and signal-to-noise ratios, are investigated. After more than one decade of attempts to establish gallium arsenide as a sensor material for photon counting detectors, our results represent a breakthrough in obtaining detector-grade material. The sensor we introduce is therefore suitable for high resolution X-ray imaging applications.

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“…The resistivity was measured to be cm in the linear range, which is in agreement with previous measurements carried out using the same batch of material [23].…”

Section: A Detector Characterizationsupporting

confidence: 89%

Section: Detector Fabrication and Chip Descriptionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Performance of a Medipix3RX Spectroscopic Pixel Detector With a High Resistivity Gallium Arsenide Sensor

Hamann

Koenig

Zubér

et al. 2015

IEEE Trans. Med. Imaging

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“…As discussed earlier [1][2][3][4], gallium arsenide compensated with chromium is a promising material for semiconductor detectors with X-ray photon energies ranging from 15 to 60 keV. The results of investigations on the variations in the pulse height distribution with the electrophysical characteristics of the detector material and in the output signal (photocurrent and count rate) with the X-ray intensity and bias voltage are presented.…”

Section: Contentsmentioning

confidence: 97%

“…The prototypes were compatible with Medipix 3/Timepix readout ASICs. The GaAs:Cr sensors were bump-bonded to Medipix/Timepix ASICs and tested at the FMF and IPS [4]. Images were obtained using a 512 × 768 pixel GaAs sensor (see figures 8(a) and (b)).…”

Section: Prototype Gaas:cr Imaging Detectorsmentioning

confidence: 99%

Chromium-compensated GaAs detector material and sensors

Budnitsky¹,

Tyazhev²,

Novikov³

et al. 2014

J. Inst.

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Results obtained from numerical calculations of and experimental studies on the pulse height distribution inherent in ionizing radiation gallium arsenide sensors as a function of the design features of the devices and electrophysical characteristics of the detector material are presented. It is shown that the pulse height distribution is defined by the distribution pattern of the nonequilibrium charge carrier lifetime and by the electric field profile in the bulk of the sensor. Investigations on the detector sensitivity to X-ray energies in the range between 40 and 150 keV were performed. The sensor polarization was found to produce only a marginal effect compensated by an increase in the bias voltage. Prototype pixel sensors measuring 256 × 256 and 512 × 768 pixels with a 55 µm pitch and a 500 µm thick sensitive layer were produced. The dependence of the photocurrent and count rate on the X-ray radiation intensity and bias voltage applied to the sensor was examined. In the 40-80 keV energy range, the maximum count rate amounted to 800 kHz/pixel for a negative sensor bias voltage of 800 V. The sensors are demonstrated to provide spatial resolution varying with the pixel pitch and to enable high-quality X-ray images to be obtained.

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Overview of GaAs und CdTe Pixel Detectors Using Medipix Electronics

Fiederle

Procz

Hamann

et al. 2020

Crystal Research and Technology

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GaAs and CdTe pixel detectors have been developed over the last few decades. The applications of these detectors include X‐ and gamma‐ray detectors working at room temperature. Fundamental properties such as detection efficiency and noise are determined by the material properties of the sensor material. Different materials have been evaluated over the years in search of the best choice for different types of radiation. This article describes the properties of GaAs and CdTe materials for single photon processing pixel detectors using the Medipix electronics.

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Characterization of photon counting pixel detectors based on semi-insulating GaAs sensor material

Cited by 23 publications

References 9 publications

Performance of a Medipix3RX Spectroscopic Pixel Detector With a High Resistivity Gallium Arsenide Sensor

Performance of a Medipix3RX Spectroscopic Pixel Detector With a High Resistivity Gallium Arsenide Sensor

Chromium-compensated GaAs detector material and sensors

Overview of GaAs und CdTe Pixel Detectors Using Medipix Electronics

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