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Budniak AK, Killilea NA, Zelewski SJ, Sytnyk M, Kauffmann Y, Amouyal Y, Kudrawiec R, Heiss W, Lifshitz E. Exfoliated CrPS 4 with Promising Photoconductivity. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1905924. [PMID: 31805222 DOI: 10.1002/smll.201905924] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/11/2019] [Indexed: 06/10/2023]
Abstract
Layered semiconductors have attracted significant attention due to their diverse physical properties controlled by composition and the number of stacked layers. Herein, large crystals of the ternary layered semiconductor chromium thiophosphate (CrPS4 ) are prepared by a vapor transport synthesis. Optical properties are determined using photoconduction, absorption, photoreflectance, and photoacoustic spectroscopy exposing the semiconducting properties of the material. A simple, one-step protocol for mechanical exfoliation onto a transmission electron microscope grid is developed, and multiple layers are characterized by advanced electron microscopy methods, including atomic resolution elemental mapping confirming the structure by directly showing the positions of the columns of different elements' atoms. CrPS4 is also liquid exfoliated, and in combination with colloidal graphene, an ink-jet-printed photodetector is created. This all-printed graphene/CrPS4 /graphene heterostructure detector demonstrates a specific detectivity of 8.3 × 108 (D*). This study shows a potential application of both bulk crystal and individual flakes of CrPS4 as active components in light detection, when introduced as ink-printable moieties with a large benefit for manufacturing.
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Affiliation(s)
- Adam K Budniak
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa, 3200003, Israel
| | - Niall A Killilea
- Materials Science Department (Materials for Electronics and Energy Technology), Friedrich-Alexander Universität Erlangen-Nürnberg, Energy Campus Nürnberg, Fürtherstrasse 250, Nürnberg, 90429, Germany
| | - Szymon J Zelewski
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland
| | - Mykhailo Sytnyk
- Materials Science Department (Materials for Electronics and Energy Technology), Friedrich-Alexander Universität Erlangen-Nürnberg, Energy Campus Nürnberg, Fürtherstrasse 250, Nürnberg, 90429, Germany
| | - Yaron Kauffmann
- Department of Materials Science and Engineering, Technion-Israel Institute of Technology, Haifa, 3200003, Israel
| | - Yaron Amouyal
- Department of Materials Science and Engineering, Technion-Israel Institute of Technology, Haifa, 3200003, Israel
| | - Robert Kudrawiec
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland
| | - Wolfgang Heiss
- Materials Science Department (Materials for Electronics and Energy Technology), Friedrich-Alexander Universität Erlangen-Nürnberg, Energy Campus Nürnberg, Fürtherstrasse 250, Nürnberg, 90429, Germany
| | - Efrat Lifshitz
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa, 3200003, Israel
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Yang Y, Chen O, Angerhofer A, Cao YC. Radial-Position-Controlled Doping in CdS/ZnS Core/Shell Nanocrystals. J Am Chem Soc 2006; 128:12428-9. [PMID: 16984188 DOI: 10.1021/ja064818h] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this paper, we report a new doping approach using a three-step synthesis to make high-quality Mn-doped CdS/ZnS core/shell nanocrystals. This approach allows precise control of the Mn radial position and doping level in the core/shell nanocrystals. On the basis of this synthetic advance, we have demonstrated the first example in which optical properties of Mn-doped nanocrystals strongly depend on Mn radial positions inside the nanocrystals. In addition, we have synthesized nanocrystals with a room-temperature Mn-emission quantum yield of 56%, which is nearly twice as high as that of the best Mn-doped nanocrystals reported previously. Nanocrystals with such a high-emission quantum yield are very important to applications such as nanocrystal-based biomedical diagnosis.
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Affiliation(s)
- Yongan Yang
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, USA
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Zubkov T, Stahl D, Thompson TL, Panayotov D, Diwald O, Yates JT. Ultraviolet Light-Induced Hydrophilicity Effect on TiO2(110)(1×1). Dominant Role of the Photooxidation of Adsorbed Hydrocarbons Causing Wetting by Water Droplets. J Phys Chem B 2005; 109:15454-62. [PMID: 16852960 DOI: 10.1021/jp058101c] [Citation(s) in RCA: 256] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The UV photoproduction of a hydrophilic TiO(2)(110)(1x1) surface has been investigated in a pressurized ultrahigh vacuum apparatus under controlled conditions of hydrocarbon concentration in oxygen gas at 1 atm pressure. Water droplet contact angles have been measured continuously as the droplet is exposed to UV irradiation, yielding the first observations of a sudden wetting process during irradiation. Using hexane as a model hydrocarbon, it is found that when low partial pressures of hexane are present, the sudden onset of surface wetting occurs during UV irradiation after an induction period under photooxidation conditions. The induction period to reach the critical condition for sudden wetting increases when the partial pressure (and equilibrium surface coverage) of hexane is increased. These results indicate that the removal of adsorbed hydrocarbons by photooxidation is the critical factor leading to the UV-induced hydrophilicity phenomenon on TiO(2). The phenomenon does not occur in the absence of O(2) gas. A concept concerned with kinetic screening of the TiO(2)-H(2)O interface from O(2) by water droplets is presented to explain the observation of sudden wetting in our experiments, compared to gradual wetting which is observed following UV irradiation in all other experiments reported in the literature. Complementary infrared spectroscopy measurements of the effect of UV irradiation in an O(2) atmosphere on adsorbed Ti-OH groups and on adsorbed H(2)O on the surface of a high-area TiO(2) powder show that no spectroscopic changes occur. This indicates that UV-induced changes in the -OH coverage or the nature of -OH bonding to TiO(2), as suggested by others, cannot be used to explain the photoinduced hydrophilicity effect.
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Affiliation(s)
- Tykhon Zubkov
- Surface Science Center, Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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Meier DC, Goodman DW. The Influence of Metal Cluster Size on Adsorption Energies: CO Adsorbed on Au Clusters Supported on TiO2. J Am Chem Soc 2004; 126:1892-9. [PMID: 14871122 DOI: 10.1021/ja030359y] [Citation(s) in RCA: 224] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Infrared reflection absorption spectroscopy (IRAS) has been used to study CO adsorption on Au clusters ranging in size from 1.8 to 3.1 nm, supported on TiO(2). The adsorbed CO vibrational frequency blue-shifts slightly (approximately 4 cm(-)(1)) compared to that adsorbed on bulk Au, whereas the heats of adsorption (-DeltaH(ads)) increase sharply with decreasing cluster size, from 12.5 to 18.3 kcal/mol.
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Affiliation(s)
- Douglas C Meier
- Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, TX 77842-3012, USA
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Sibley S, Francis A, Lifshitz E, Clément R. Magnetic resonance studies of intercalated, two-dimensional transition metal chalcogenophosphate lattices. Colloids Surf A Physicochem Eng Asp 1994. [DOI: 10.1016/0927-7757(93)02622-l] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Smithers GW, Sammons RD, Goodhart PJ, LoBrutto R, Reed GH. Stereochemical control over Mn(II)-thio versus Mn(II)-oxy coordination in adenosine 5'-O-(1-thiodiphosphate) complexes at the active site of creatine kinase. Biochemistry 1989; 28:1597-604. [PMID: 2541758 DOI: 10.1021/bi00430a026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The stereochemical configurations of the Mn(II) complexes with the resolved epimers of adenosine 5'-O-(1-thiodiphosphate) (ADP alpha S), bound at the active site of creatine kinase, have been determined in order to assess the relative strengths of enzymic stereoselectivity versus Lewis acid/base preferences in metal-ligand binding. Electron paramagnetic resonance (EPR) data have been obtained for Mn(II) in anion-stabilized, dead-end (transition-state analogue) complexes, in ternary enzyme-MnIIADP alpha S complexes, and in the central complexes of the equilibrium mixture. The modes of coordination of Mn(II) at P alpha in the nitrate-stabilized, dead-end complexes with each epimer of ADP alpha S were ascertained by EPR measurements with (Rp)-[alpha-17O]ADP alpha S and (Sp)-[alpha-17O]ADP alpha S. The EPR spectrum for the complex with (Rp)-[alpha-17O]ADP alpha S showed inhomogeneous broadening due to unresolved superhyperfine coupling from coordinated 17O at P alpha. By contrast, the EPR spectrum for Mn(II) in complex with (Sp)-[alpha-17O]ADP alpha S is indistinguishable from that obtained for a matched sample with unlabeled (Sp)-ADP alpha S. A reduction in the magnitude of the 55Mn hyperfine coupling constant in the spectrum for the complex containing (Sp)-ADP alpha S is indicative of Mn(II)-thio coordination at P alpha.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- G W Smithers
- Institute for Enzyme Research, Graduate School, University of Wisconsin, Madison 53705
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