X-ray imaging with PbI2-based A-Si:H flat panel detectors

Shah, K.S.; Street, R. A.; Dmitriyev, Y.; Bennett, Paul R.; Cirignano, L.; Klugerman, M.; Squillante, Michael R.; Entine, G.

doi:10.1016/s0168-9002(00)00857-3

Cited by 84 publications

(32 citation statements)

References 9 publications

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“…It should be noted that the diffraction results shown in Fig. 2 are somehow comparable to the ones obtained by other researches using other deposition techniques: the peak positions are the same with the peaks showing different relative intensities [4]. The crystallite size varies as a function of deposition temperature as can be observed in Fig.…”

Section: Structural Propertiessupporting

confidence: 85%

“…This material has an optical gap of 2.4 eV [2], and an hexagonal structure made of a plane of lead atoms between two planes of iodine atoms [2,3]. The material can be used in the direct detection configuration where the X-ray photons generate electronic charge inside the semiconductor [4,5]. Other authors have fabricated prototype detectors using this material [4].…”

Section: Introductionmentioning

confidence: 99%

“…The material can be used in the direct detection configuration where the X-ray photons generate electronic charge inside the semiconductor [4,5]. Other authors have fabricated prototype detectors using this material [4]. Their experiments show high resolution and sensitivity for real time imaging, thus showing the material potentiality for medical applications in the future.…”

Section: Introductionmentioning

confidence: 99%

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Fabrication and characterization of thin films of PbI2 for medical imaging

Condeles

Martins

Santos

et al. 2004

Journal of Non-Crystalline Solids

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Section: Structural Propertiessupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fabrication and characterization of thin films of PbI2 for medical imaging

Condeles

Martins

Santos

et al. 2004

Journal of Non-Crystalline Solids

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“…One drawback is that lead iodide decomposes when heated or melted, which leads to a lack of stoichiometry [18], [27]. 0018-9499/02$17.00 © 2002 IEEE Lead-iodide polycrystalline films have been grown by evaporation [15]- [17], [19]- [21] and sublimation [18], [20], [21] with thickness from 35 [20] to 250 m [17] and grain sizes from 1 [17] to 80 m [20]. They have been characterized by optical microscopy [20], [21], scanning electron microscopy [17], atomic force microscopy [20], [21], X-ray diffraction [17], [20], [21], and low-temperature photoluminescence [20], [21].…”

Section: Introductionmentioning

confidence: 99%

Toward epitaxial lead-iodide films for X-ray digital imaging

Fornaro

Saucedo

Mussio

et al. 2002

IEEE Trans. Nucl. Sci.

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Lead iodide purified by repeated evaporation was used for growing films by the physical vapor deposition method. Purity and stoichiometry of the starting material were determined by ICP and wet techniques. Films were grown onto 2 in 2 in glass substrates with palladium as rear electrode. Lead-iodide films were grown by evaporating the starting material at 460 C in high-purity Ar atmosphere (600 mmHg) for 1 to 4 days, depending on the film thickness. The substrate temperature was prefixed from 200 to 250 C. Film thickness was measured by transmission of the 59.5 keV radiation from 241 Am giving values from 35 to 50 m (5%). Optical microscopy was performed on the films for determining crystallinity and grain size. Films were characterized by X-ray diffraction and texture was calculated as [6 (0 0 )] [6 ( )]. Correlations between grain size, crystallinity, and growth-preferred orientation along the -axis perpendicular to the substrate with substrate temperature were confirmed. The texture of the films strongly increases with substrate temperature, and films with texture of about 90% were obtained. Correlation between starting material purity and stoichiometry with epitaxial growth were also found. For measuring electrical and X-ray response properties detectors were assembled by front palladium thermal deposition, palladium wire attachment, and acrylic encapsulation. Resistivity values of 5 10 14 cm and current density values of 5 pA/cm 2 at 30 V were obtained. X-ray film response was checked by irradiating with an X-ray beam, giving linear response with exposure rate and sensitivities of about 0.35 C/R.cm 2 . Again, a correlation between electrical properties with the substrate temperature and epitaxial growth was confirmed. Finally, results were compared with previous ones for the same and alternative materials.Index Terms-Compound semiconductor films, lead iodide, X-ray imaging.

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“…Nevertheless, it is an important alternative material for low-energy X-ray spectrometry and its inherent applications. Lately, it has became a potential material for polycrystalline films for direct digital X-ray imaging as well [3], [4].…”

Section: Introductionmentioning

confidence: 99%

New ways for purifying lead iodide appropriate as spectrometric grade material

Saucedo

Fornaro

Mussio

et al. 2002

IEEE Trans. Nucl. Sci.

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In order to overcome some unsolved problems of lead iodide purification such as lack of stoichiometry, decomposition, and polytype admixture, several purification methods were compared. Lead iodide from different suppliers and synthesized from lead nitrate and potassium iodide was purified by zone refining, by zone refining followed by sublimation, by repeated sublimation and by repeated evaporation under different conditions. Purification methods were evaluated by studying parameters of the purified material like decomposition, stoichiometry, purity, and polytype composition, and also taking into account purification yield and rate. Stoichiometry was measured by wet procedures, purity by inductively coupled plasma (ICP) and polytypes by powder X-ray diffraction. Sublimation and evaporation give the best stoichiometry (PbI 1 90 ), especially when compared with zone refining (PbI 1 40 ). Purification by 100 zone refining passes gives similar impurity concentration to purification by three evaporations. Furthermore, evaporation exhibits maximum yield and rate (16%/day). Therefore, the work performed indicates that evaporation in Ar atmosphere is the quickest and most efficient purification method for producing spectrometric grade lead iodide, avoiding material decomposition and achieving high purity, maintaining the best stoichiometry.

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X-ray imaging with PbI2-based A-Si:H flat panel detectors

Cited by 84 publications

References 9 publications

Fabrication and characterization of thin films of PbI2 for medical imaging

Fabrication and characterization of thin films of PbI2 for medical imaging

Toward epitaxial lead-iodide films for X-ray digital imaging

New ways for purifying lead iodide appropriate as spectrometric grade material

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