Thickness dependence of structure in thin films of low-temperature silver selenide

Günter, John R.; Keusch, P.

doi:10.1016/0304-3991(93)90236-q

Cited by 39 publications

(46 citation statements)

References 30 publications

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“…It has been previously proposed that the low-temperature form of Ag 2 Se could, in fact, possess two different polymorphic forms depending on the sizes of the single-crystalline domains. [25] A conclusive statement on this issue has been elusive because the polycrystalline films used in these studies were characterized by domains sizes spreading across a very broad range. To our knowledge, the nanowire system described here represents the first example of 1D nanostructures exhibiting a diameter-dependent crystal structure.…”

Section: Size Dependence For the Structure Of Ag 2 Se Nanowiresmentioning

confidence: 99%

Synthesis and Characterization of Crystalline Ag ₂ Se Nanowires Through a Template‐Engaged Reaction at Room Temperature

Gates

Mayers

et al. 2002

Adv Funct Materials

150

100

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Single‐crystalline Ag2Se nanowires have been successfully synthesized through a template‐engaged topotactic reaction in which nanowires of trigonal selenium were transformed into Ag2Se by reacting with aqueous AgNO3 solutions at room temperature (RT). An interesting size‐dependent transition between two crystal structures has also been observed for this newly synthesized one‐dimensional system: The Ag2Se nanowires adopted a tetragonal structure when their diameters were less than ∼40 nm; an orthorhombic structure was found to be more favorable as the diameter of these nanowires was increased beyond 40 nm. Since this reaction can be carried out at ambient pressure and temperature, it should be straightforward to scale up the entire process for the high‐volume production of Ag2Se nanowires with well‐controlled sizes and crystal structures. These highly uniform nanowires of single‐crystalline Ag2Se are potentially useful as photosensitizers, superionic conductors, magnetoresistive compounds, or thermoelectric materials. This work also represents the first demonstration of a template‐engaged process capable of generating single‐crystalline nanowires from the solution‐phase and at RT.

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Section: Size Dependence For the Structure Of Ag 2 Se Nanowiresmentioning

confidence: 99%

Synthesis and Characterization of Crystalline Ag ₂ Se Nanowires Through a Template‐Engaged Reaction at Room Temperature

Gates

Mayers

et al. 2002

Adv Funct Materials

150

100

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“…[5][6][7][8] Furthermore, entirely new crystal phases can arise on the nanoscale that have no known counterparts in bulk. [9][10][11][12][13] Because the physical properties of a material are linked to its crystalline structure, the ability to isolate new or difficult-to-access metastable structures on the nanoscale holds promise for the discovery of novel functional materials with properties different from, and possibly superior to, the properties of more thermodynamically stable materials. [14][15][16][17][18] To synthetically target such materials, it is important to consider that a metastable state is only isolable if, under some set of conditions, that state represents a thermodynamic minimum.…”

mentioning

confidence: 99%

Ligand-Mediated Phase Control in Colloidal AgInSe₂ Nanocrystals

2020

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Synthetic studies of colloidal nanoparticles that crystallize in metastable structures represent an emerging area of interest in the development of novel functional materials, as metastable nanomaterials may exhibit unique properties when compared to their counterparts that crystallize in thermodynamically preferred structures. Herein, we demonstrate how phase control of colloidal AgInSe2 nanocrystals can be achieved by performing reactions in the presence, or absence, of 1-dodecanethiol. The thiol plays a crucial role in formation of metastable AgInSe2 nanocrystals, as it mediates an in-situ topotactic cation exchange from an orthorhombic Ag2Se intermediate to a metastable orthorhombic phase of AgInSe2. We provide a detailed mechanistic description of this cation exchange process to structurally elucidate how the orthorhombic phase of AgInSe2 forms. Density functional theory calculations suggest that the metastable orthorhombic phase of AgInSe2 is metastable by a small margin, at 10 meV/atom above the thermodynamic ground state. In the absence of 1-dodecanethiol, a mixture of Ag2Se nanocrystal intermediates form that convert through kinetically slow, non-topotactic exchange processes to yield the thermodynamically preferred chalcopyrite structure of AgInSe2. Finally, we offer new insight into the prediction of novel metastable multinary nanocrystal phases that do not exist on bulk phase diagrams.

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“…The thickness of Ag 2 Se samples affects their electric resistivity, energy gap [41], and even their structure [42]. Contradictory descriptions of Ag 2 Se structure at low temperature reported by many authors as tetragonal, orthorhombic, monoclinic, pseudoorthorhombic, triclinic, and cubic (fcc) is reviewed shortly in [42]. Such a situation results in ''the large volume of inconsistent information available from the literature'' [43].…”

Section: Elusive Phase Transition In Ag 2 Se and Its Similarity With mentioning

confidence: 96%

“…Together with conventional problems of stoichiometry, homogeneity, and quenching-annealing, the very size and shape of a sample turned out to be critical for the fundamental properties of the substance. The thickness of Ag 2 Se samples affects their electric resistivity, energy gap [41], and even their structure [42]. Contradictory descriptions of Ag 2 Se structure at low temperature reported by many authors as tetragonal, orthorhombic, monoclinic, pseudoorthorhombic, triclinic, and cubic (fcc) is reviewed shortly in [42].…”

Section: Elusive Phase Transition In Ag 2 Se and Its Similarity With mentioning

confidence: 98%

Probable metal–insulator transition in Ag4SSe

Drebushchak

Palyanova

Seryotkin

et al. 2015

Journal of Alloys and Compounds

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Thickness dependence of structure in thin films of low-temperature silver selenide

Cited by 39 publications

References 30 publications

Synthesis and Characterization of Crystalline Ag ₂ Se Nanowires Through a Template‐Engaged Reaction at Room Temperature

Synthesis and Characterization of Crystalline Ag ₂ Se Nanowires Through a Template‐Engaged Reaction at Room Temperature

Ligand-Mediated Phase Control in Colloidal AgInSe₂ Nanocrystals

Probable metal–insulator transition in Ag4SSe

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Thickness dependence of structure in thin films of low-temperature silver selenide

Cited by 39 publications

References 30 publications

Synthesis and Characterization of Crystalline Ag 2 Se Nanowires Through a Template‐Engaged Reaction at Room Temperature

Synthesis and Characterization of Crystalline Ag 2 Se Nanowires Through a Template‐Engaged Reaction at Room Temperature

Ligand-Mediated Phase Control in Colloidal AgInSe2 Nanocrystals

Probable metal–insulator transition in Ag4SSe

Contact Info

Product

Resources

About

Synthesis and Characterization of Crystalline Ag ₂ Se Nanowires Through a Template‐Engaged Reaction at Room Temperature

Synthesis and Characterization of Crystalline Ag ₂ Se Nanowires Through a Template‐Engaged Reaction at Room Temperature

Ligand-Mediated Phase Control in Colloidal AgInSe₂ Nanocrystals