Solution grown mercuric iodide crystals as low-energy gamma-ray conduction type detectors

Rao, Madhumati; Verma, Jai; Patro, A.P.

doi:10.1088/0022-3727/13/8/024

Cited by 8 publications

(6 citation statements)

References 7 publications

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“…Previously reported solution growth methods of α-HgI 2 bulk crystals generally have employed a solvent evaporation (e.g., ethanol, dimethyl sulfoxide, CH 3 I, etc.) method. ,− However, the nonuniform evaporation rate may induce pores and stress defects into the growing α-HgI 2 crystal, which are unfavorable for the practical use of the crystal.…”

Section: Introductionmentioning

confidence: 99%

Crystal Growth of α-HgI₂ by the Temperature Difference Method for High Sensitivity X-ray Detection

Zhang

Zheng

Chen

et al. 2015

Crystal Growth & Design

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α-HgI 2 is a promising material for room temperature X-ray detection. A facile temperature difference method is designed to grow 4 × 4 × 2 mm 3 α-HgI 2 bulk crystal from KI aqueous solution. Characterization results indicate the as-grown high quality crystals are single-crystalline and possess a standard bandgap (E g = 2.16 eV at 300 K) and high electrical resistivity (10 10 Ω·cm). Utilizing the as-grown crystal, moreover, a photoconductive type prototype X-ray detector is fabricated. The detector behaves at high X-ray sensitivity, which is improved by one order of magnitude in comparison with previous results from solution grown α-HgI 2 . In addition to α-HgI 2 , the crystal growth of other halides materials which are used for X-ray detection, e.g., PbI 2 , HgBr 2 , BiI 3 , may also benefit from the presented temperature difference method.

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Section: Introductionmentioning

confidence: 99%

Crystal Growth of α-HgI₂ by the Temperature Difference Method for High Sensitivity X-ray Detection

Zhang

Zheng

Chen

et al. 2015

Crystal Growth & Design

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“…(2) where U is the thermal velocity of carriers, S is the capture cross section of the traps and N , is the number of recombination centres per unit volume. The rate of trap emptying is given by (3) where n, is the density of trapped electrons, f is the frequency factor and E is the activation energy of the traps. The frequency factor is defined by…”

Section: X-ray Irradiated Crystalsmentioning

confidence: 99%

“…a-Hgl,, a wide-handgap semiconductor, has heen proved to he well suited for the fabrication of xand y-ray detectors operable at room temperature [l, 21. The performance of these detectors i s actually limited by charge carrier trapping that prevents the complete collection of the charge carriers [3,4]. In order to understand the trapping mechanism o f charge carriers in a-HgI, crystals many TSC measurements have already heen performed on crystals, grown in different conditions [5-151. Generally, a drawback of a-HgI, detectors i s the degradation of their resolution by aging.…”

Section: Introductionmentioning

confidence: 99%

Study of charge carrier trapping in solution-grown alpha -HgI₂crystals by thermally stimulated currents

Suryanarayana¹,

Acharya²,

Nicolau³

1992

Semicond. Sci. Technol.

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u-Hgl, crystals grown in solution, crystals irradiated by x-or y-rays, crystals aged in air, crystals aged after being polarized in a high DC field, and crystals stored in an iodine atmosphere were studied by thermally stimulated currents (TSC). The general TSC spectrum of the crystals shows two peaks: at 170 and 230 K. X-ray irradiation generates deep-donor-type traps and decreases the lifetime of the charge carriers. y-ray irradiation introduces a large number of deep traps closely spacedain energy. By aging the crystals in air deep donor traps are introduced into a narrow layer close to the surface of the crystals. Crystals aged in air and polarized in a high DC field show a depletion of the concentration of the deep donor traps in the active zone close to the surface induced by the field. The storage of the crystals in an iodine atmosphere prevents their degradation by aging. Apparently iodine diffusion into the crystals suppresses the slight Hg-rich deviation from the stoichiometry in crystals

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“…The third phase of this material is known as orange HgI 2 , only having differences in the positions of the mercury atoms between the atoms of iodine. Thus, the fusion technique is not recommended for the growth of HgI 2 , other techniques, such as "Physical Vapor Transport" (PVT) (Zhou et al, 2003) or "Saturated Solution" (Rao et al, 1979) are more adequated for HgI 2 growth.…”

Section: Introductionmentioning

confidence: 99%

Optimization of the HgI2 Crystal Preparation for Application as a Radiation Semiconductor Detector

Martins¹,

Santos²,

Ferraz³

et al. 2018

SET

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The effect of HgI 2 crystal encapsulation using different polymer resins, with the intent of avoiding the oxidation of the crystal surface, was evaluated in this work. The crystal was purified and grown by the physical vapor transport (PVT) technique modified. Systematic measurements were carried out for evaluating the stoichiometry, structure orientation, surface morphology and impurity of the crystal grown. The purer region of the crystal grown was selected to be prepared as a radiation detector, applying water-based conductive ink contacts and copper wire on the crystal surfaces. After that, the crystal was encapsulated with a polymeric resin which insulates atmospheric gases, aiming to improve the stability of the HgI 2 detector. Four resins were used for crystal encapslation and the performance of the detector depended on the composition of the resins used. Among the four resins studied to evaluate the influence of encapsulation on the performance of crystals, as a radiation detector, the best result of resistivity and energy spectrum was obtained for the resin #3 (50% -100% of Methylacetate and 5% -10% of n-butylacetate). The encapsulation of crystals with polymer resins, performed with the intent of avoiding the oxidation of the crystal surface, did not compromise the measurements and were fully capable of detecting the presence of gamma radiation. The stability of the encapsulated HgI2 crystal detector was of up to 78 hs, while the stability found for HgI 2 detector no encapsulated was in order 3 ~4 hs.

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Solution grown mercuric iodide crystals as low-energy gamma-ray conduction type detectors

Cited by 8 publications

References 7 publications

Crystal Growth of α-HgI₂ by the Temperature Difference Method for High Sensitivity X-ray Detection

Crystal Growth of α-HgI₂ by the Temperature Difference Method for High Sensitivity X-ray Detection

Study of charge carrier trapping in solution-grown alpha -HgI₂crystals by thermally stimulated currents

Optimization of the HgI2 Crystal Preparation for Application as a Radiation Semiconductor Detector

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Solution grown mercuric iodide crystals as low-energy gamma-ray conduction type detectors

Cited by 8 publications

References 7 publications

Crystal Growth of α-HgI2 by the Temperature Difference Method for High Sensitivity X-ray Detection

Crystal Growth of α-HgI2 by the Temperature Difference Method for High Sensitivity X-ray Detection

Study of charge carrier trapping in solution-grown alpha -HgI2crystals by thermally stimulated currents

Optimization of the HgI2 Crystal Preparation for Application as a Radiation Semiconductor Detector

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Product

Resources

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Crystal Growth of α-HgI₂ by the Temperature Difference Method for High Sensitivity X-ray Detection

Crystal Growth of α-HgI₂ by the Temperature Difference Method for High Sensitivity X-ray Detection

Study of charge carrier trapping in solution-grown alpha -HgI₂crystals by thermally stimulated currents