Dimensional Reduction: A Design Tool for New Radiation Detection Materials

Androulakis, J.; Peter, Sebastian C.; Li, Hao; Malliakas, Christos D.; Peters, John A.; Liu, Zhifu; Wessels, Bruce W.; Song, Jung Hwan; Jin, Hosub; Freeman, Arthur J; Kanatzidis, Mercouri G.

doi:10.1002/adma.201102450

Cited by 199 publications

(185 citation statements)

References 26 publications

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“…These materials are used, e.g., in gas sensors or detectors for high-energy radiation. 1 The crystal structures of most compounds in the ternary systems M−T−Q consist of oligomeric or polymeric one-, two-, or three-dimensional (1D, 2D, 3D) anions formed by condensed TQ 4 tetrahedra. 2 Among the large number of chalcogenotrielates, however, only a few compounds featuring polychalcogenide units are known.…”

Section: ■ Introductionmentioning

confidence: 99%

Interconversion of One-Dimensional Thiogallates Cs₂[Ga₂(S₂)_2–xS_2+x] (x = 0, 1, 2) by Using High-Temperature Decomposition and Polysulfide-Flux Reactions

Friedrich

Schlösser

Pfitzner

2017

Crystal Growth & Design

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The potential of cesium polysulfide-flux reactions for the synthesis of chalcogenogallates was investigated by using X-ray diffraction and Raman spectroscopy. An investigation of possible factors influencing the product formation revealed that only the polysulfide content x in the Cs 2 S x melts has an influence on the crystalline reaction product. From sulfur-rich melts (x > 7), CsGaS 3 is formed, whereas sulfur-poor melts (x < 7) lead to the formation of Cs 2 Ga 2 S 5 . In situ investigations using hightemperature Raman spectroscopy revealed that the crystallization of these solids takes place upon cooling of the melts. Upon heating, CsGaS 3 and Cs 2 Ga 2 S 5 release gaseous sulfur due to the degradation of S 2 2− units. This decomposition of CsGaS 3 to Cs 2 Ga 2 S 5 and finally to CsGaS 2 -mC16 was further studied in situ by using high-temperature X-ray powder diffraction. A combination of the polysulfide reaction route and the high-temperature decomposition leads to the possibility of the directed interconversion of these thiogallates. The presence of disulfide units in the anionic substructures of these thiogallates has a significant influence on the electronic band structures and their optical properties. This influence was studied by using UV/vis-diffuse reflectance spectroscopy and DFT simulations, revealing a trend of smaller band gaps with increasing S 2 2− content. ■ INTRODUCTIONGroup 13 chalcogenometallates containing alkali metal cations M x T y Q z (M = alkali metal, T = triel, Q = chalcogen) are interesting materials due to their semiconducting properties. These materials are used, e.g., in gas sensors or detectors for high-energy radiation. 1 The crystal structures of most compounds in the ternary systems M−T−Q consist of oligomeric or polymeric one-, two-, or three-dimensional (1D, 2D, 3D) anions formed by condensed TQ 4 tetrahedra. 2 Among the large number of chalcogenotrielates, however, only a few compounds featuring polychalcogenide units are known. Incorporation of polychalcogenide units into the anionic structures leads to more exotic structural motives. The crystal structures of mixed-valent chalcogenometallates like CsGaQ 3 , 3,4 Cs 2 Ga 2 Q 5 , 5,6 CsAlTe 3 7 and several chalcogenoborates 8−11 show 1D anionic chains containing Q 2 2− or Q 3 2− units (Q = S, Se). The mixed-valent nature of the chalcogen in these compounds should significantly influence the properties of these semiconductors. Therefore, it is necessary to understand the reactive behavior of these compounds and the conditions necessary for their formation in order to design compounds with desired properties. Molten polysulfide fluxes are an established method for the synthesis of substances featuring polysulfide anions. 12−14 Due to an enhanced diffusion rate at comparably low temperatures in these fluxes, the formation of thermodynamically metastable compounds is favored as compared to high-temperature reactions. Furthermore, the properties of these fluxes (basicity, viscosity, etc.) can be fine-tuned by adjusti...

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Section: ■ Introductionmentioning

confidence: 99%

Interconversion of One-Dimensional Thiogallates Cs₂[Ga₂(S₂)_2–xS_2+x] (x = 0, 1, 2) by Using High-Temperature Decomposition and Polysulfide-Flux Reactions

Friedrich

Schlösser

Pfitzner

2017

Crystal Growth & Design

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“…6,7 Single crystals were subsequently grown by the Bridgman method using a sealed quartz tube as the crucible. The grown ingots were analyzed by Laue back-scattered reflection to verify their single crystalline nature.…”

Section: Methodsmentioning

confidence: 99%

“…[2][3][4][5] Recently, we have observed that the ternary compound Cs 2 Hg 6 S 7 with a band gap of 1.63 eV shows considerable promise as a room-temperature x-ray detector. 6,7 For this compound, the starting polycrystalline materials with higher purity is utilized for growing Cs 2 Hg 6 S 7 crystals. Crystals with high resistivity of the order of 10 8 X cm were grown.…”

Section: Introductionmentioning

confidence: 99%

Photo-Induced Current Transient Spectroscopy of Semi-insulating Single Crystal Cs2Hg6S7

Liu

Peters

et al. 2014

Journal of Elec Materi

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The ternary compound Cs 2 Hg 6 S 7 has shown considerable promise as a wide gap semiconductor for hard radiation detection at room temperature. We report on the measurement of defect levels in Cs 2 Hg 6 S 7 using photo-induced current transient spectroscopy. We observe a series of defect levels with mean activation energies of 0.053, 0.052, 0.34, 0.35, and 0.46 eV. The defects are attributed to Cs vacancies and Cs and Hg antisite defects. Defect capture cross-sections are in the range 10 À20 -10 À15 cm 2 .

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“…For any semiconductor material to be used in radiation detector applications that can be operable at room temperature, the material should have possibly low impurity concentration [12], the highest possible crystalline quality [13], a large bandgap, and a high resistivity [3] at the same time. In this regard, the data of Fig.…”

Section: Discussionmentioning

confidence: 99%

“…To fabricate such a high-quality semiconductor-based radiation detector, high-quality and high-purity semiconductor single crystals are needed. In addition, materials consisting of high atomic number elements are needed due to the higher probability of an incoming radiation beam interaction with valence electrons [3]. In this regard, a TlBr (atomic numbers: Tl-81, Br-35) compound semiconductor with a bandgap of ∼2.7 eV is considered as one of the promising candidates for various applications, and was intensively researched by various research groups [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Characteristics of TlBr single crystals grown using the vertical Bridgman-Stockbarger method for semiconductor-based radiation detector applications

Kim

et al. 2016

Materials Science-Poland

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TlBr single crystals grown using the vertical Bridgman-Stockbarger method were characterized for semiconductor based radiation detector applications. It has been shown that the vertical Bridgman-Stockbarger method is effective to grow highquality single crystalline ingots of TlBr. The TlBr single crystalline sample, which was located 6 cm from the tip of the ingot, exhibited lower impurity concentration, higher crystalline quality, high enough bandgap (>2.7 eV), and higher resistivity (2.5 × 10 11 Ω·cm) which enables using the fabricated samples from the middle part of the TlBr ingot for fabricating high performance semiconductor radiation detectors.

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Dimensional Reduction: A Design Tool for New Radiation Detection Materials

Cited by 199 publications

References 26 publications

Interconversion of One-Dimensional Thiogallates Cs₂[Ga₂(S₂)_2–xS_2+x] (x = 0, 1, 2) by Using High-Temperature Decomposition and Polysulfide-Flux Reactions

Interconversion of One-Dimensional Thiogallates Cs₂[Ga₂(S₂)_2–xS_2+x] (x = 0, 1, 2) by Using High-Temperature Decomposition and Polysulfide-Flux Reactions

Photo-Induced Current Transient Spectroscopy of Semi-insulating Single Crystal Cs2Hg6S7

Characteristics of TlBr single crystals grown using the vertical Bridgman-Stockbarger method for semiconductor-based radiation detector applications

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Dimensional Reduction: A Design Tool for New Radiation Detection Materials

Cited by 199 publications

References 26 publications

Interconversion of One-Dimensional Thiogallates Cs2[Ga2(S2)2–xS2+x] (x = 0, 1, 2) by Using High-Temperature Decomposition and Polysulfide-Flux Reactions

Interconversion of One-Dimensional Thiogallates Cs2[Ga2(S2)2–xS2+x] (x = 0, 1, 2) by Using High-Temperature Decomposition and Polysulfide-Flux Reactions

Photo-Induced Current Transient Spectroscopy of Semi-insulating Single Crystal Cs2Hg6S7

Characteristics of TlBr single crystals grown using the vertical Bridgman-Stockbarger method for semiconductor-based radiation detector applications

Contact Info

Product

Resources

About

Interconversion of One-Dimensional Thiogallates Cs₂[Ga₂(S₂)_2–xS_2+x] (x = 0, 1, 2) by Using High-Temperature Decomposition and Polysulfide-Flux Reactions

Interconversion of One-Dimensional Thiogallates Cs₂[Ga₂(S₂)_2–xS_2+x] (x = 0, 1, 2) by Using High-Temperature Decomposition and Polysulfide-Flux Reactions