Work function engineering in low-temperature metals

Orf, Nicholas D.; Baikie, Iain D.; Shapira, Ofer; Fink, Yoel

doi:10.1063/1.3089677

Cited by 40 publications

(27 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Samples were cleaned in situ by argon-ion sputtering. The observed contact potential for both metal electrodes is consistent with previous work function measurements (16) and the measured work function of the selenium semiconductor appears in the middle of its known bandgap, giving confidence that the surface is reasonably well prepared and representative of the device's electronic structure. Image analysis was performed with SPIP and Gwyddion.…”

Section: Methodssupporting

confidence: 76%

“…This is a surprising result because of the large work function difference between the semiconductor (15) and metals (16) and the fact that selenium is known to readily form rectifying barriers when contacted to metals in planar devices (17). Indeed in our own control experiments, thermally deposited selenium devices readily formed rectifying contacts, but until now all fiber devices behaved ohmically (see SI Text).…”

Section: Resultsmentioning

confidence: 95%

See 1 more Smart Citation

Fiber draw synthesis

Orf

Shapira²,

Sorin

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

The synthesis of a high-melting temperature semiconductor in a low-temperature fiber drawing process is demonstrated, substantially expanding the set of materials that can be incorporated into fibers. Reagents in the solid state are arranged in proximate domains within a fiber preform. The preform is fluidized at elevated temperatures and drawn into fiber, reducing the lateral dimensions and bringing the domains into intimate contact to enable chemical reaction. A polymer preform containing a thin layer of selenium contacted by tin-zinc wires is drawn to yield electrically contacted crystalline ZnSe domains of sub-100-nm scales. The in situ synthesized compound semiconductor becomes the basis for an electronic heterostructure diode of arbitrary length in the fiber. The ability to synthesize materials within fibers while precisely controlling their geometry and electrical connectivity at submicron scales presents new opportunities for increasing the complexity and functionality of fiber structures.flexible electronics | optical fiber processing | semiconductor device T hermal fiber drawing is a process in which a macrostructured preform is heated and drawn into extended lengths of microstructured fiber. New methods of increasing both the structural complexity of fibers and number of materials compatible with the drawing process are substantially expanding the functionality of photonic crystal and semiconductor device fibers (1-3). The drawing process, however, has until now been limited to materials that flow at the draw temperature. Approaches that attempt to circumvent this limitation include depositing materials inside (4-7) or onto the surface (8-11) of previously drawn fiber substrates. These methods do not take full advantage of the scaling associated with fiber drawing and are limited in their geometric complexity and the length over which uniform structures can be produced. Here this seemingly fundamental limitation is lifted by utilizing the fiber drawing process to synthesize in situ a chemical compound that has a melting temperature far exceeding the draw temperature. In this process, precursors are arranged in adjacent domains in a macroscopic preform. During thermal drawing, the fluid reactants come into contact and precipitate a new compound. To demonstrate the potential of this fiber draw synthesis method, a polymer fiber preform containing a thin seleniumsulfur layer next to eutectic tin-zinc wires is constructed and thermally codrawn into a fiber consisting of electrically contacted crystalline ZnSe domains of sub-100-nm scales at the interface between the metallic domains and selenium layer. The formation of the interface compound is the basis for an electronic heterostructure and a thermally drawn fiber device exhibiting rectifying behavior. The ability to synthesize materials during the fiber draw process while maintaining precise and arbitrary geometries should lead to substantial advances in the form and function of fibers. Results and DiscussionA fiber preform consisting of metallic Sn 74 P...

show abstract

Section: Methodssupporting

confidence: 76%

Section: Resultsmentioning

confidence: 95%

Fiber draw synthesis

Orf

Shapira²,

Sorin

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Various materials including metals [3], alloys [15,17,18], polymer [16], biomolecular films [19], have been investigated using the SKP technique. Particularly, the SKP method has been employed to explore the electronic behaviors associated with surface structures, e.g., surface adsorption/contamination, surface charge imaging, metastable state transformation, biochemical reaction, catalysis, corrosion, friction/wear as well as microcracks [8,[20][21][22]. For example, the relationship between the WF and the position, angle and orientation of microcracks was reported [3].…”

Section: Introductionmentioning

confidence: 98%

Understanding of the correlation between work function and surface morphology of metals and alloys

Xue¹,

Wang²,

Wang³

et al. 2013

Journal of Alloys and Compounds

View full text Add to dashboard Cite

“…Baikie et al [10] have described a UHV calibration method using a Hg lamp as a UV light source and a low-˚ sample in a retarding field configuration to the KP tip. Previous studies of metals [11] and ITO [12] have been performed using a combination of vacuum UPS measurements (absolute ˚) and CPD. However, these studies involve separate UHV photoemission (PE) and ambient pressure CPD measurements.…”

Section: Introductionmentioning

confidence: 99%

Ambient pressure photoemission spectroscopy of metal surfaces

Baikie¹,

Grain²,

Sutherland³

et al. 2014

Applied Surface Science

Self Cite

View full text Add to dashboard Cite

a b s t r a c tWe describe a novel photoemission technique utilizing a traditional Kelvin probe as a detector of electrons/atmospheric ions ejected from metallic surfaces (Au, Ag, Cu, Fe, Ni, Ti, Zn, Al) illuminated by a deep ultra-violet (DUV) source under ambient pressure. To surmount the limitation of electron scattering in air the incident photon energy is rastered rather than applying a variable retarding electric field as is used with UPS. This arrangement can be applied in several operational modes: using the DUV source to determine the photoemission threshold (˚) with 30-50 meV resolution and also the Kelvin probe, under dark conditions, to measure contact potential difference (CPD) between the Kelvin probe tip and the metallic sample with an accuracy of 1-3 meV. We have studied the relationship between the photoelectric threshold and CPD of metal surfaces cleaned in ambient conditions. Inclusion of a second spectroscopic visible source was used to confirm a semiconducting oxide, possibly Cu 2 O, via surface photovoltage measurements with the KP. This dual detection system can be easily extended to controlled gas conditions, relative humidity control and sample heating/cooling.

show abstract

Work function engineering in low-temperature metals

Cited by 40 publications

References 26 publications

Fiber draw synthesis

Fiber draw synthesis

Understanding of the correlation between work function and surface morphology of metals and alloys

Ambient pressure photoemission spectroscopy of metal surfaces

Contact Info

Product

Resources

About