Work function measurements on (110), (100) and (111) surfaces of silver

Chelvayohan, M.; Mee, C. H. B.

doi:10.1088/0022-3719/15/10/029

Cited by 237 publications

(135 citation statements)

References 15 publications

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“…We recently employed time-integrated nonlinear photoemission electron microscopy (PEEM) to map the LSP-enhanced electromagnetic fields in the vicinity of plasmonic silver nanoparticles supported on a silver thin film. 14 Under 400 nm fs laser irradiation, a two-photon excitation process is required to exceed the work function of silver (~4.2 eV 19 ). The photoelectron yield is thus proportional to the square of the laser intensity, or the fourth power of the local electric field.…”

Section: Imaging Localized and Propagating Surface Plasmons With Nonlmentioning

confidence: 99%

Visualizing surface plasmons with photons, photoelectrons, and electrons

El‐Khoury

Abellán

Gong

et al. 2016

Analyst

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Both photons and electrons may be used to excite surface plasmon polaritons, the collective charge density fluctuations at the surface of metal nanostructures. By virtue of their nanoscopic and dissipative nature, a detailed characterization of surface plasmon (SP) eigenmodes in real space-time ultimately requires joint nanometer spatial and femtosecond temporal resolution.The latter realization has driven significant developments in the past few years, aimed at interrogating both localized and propagating SP modes. In this mini-review, we briefly highlight different techniques employed by our own groups to visualize the enhanced electric fields associated with SPs. Specifically, we discuss recent hyperspectral optical microscopy, tipenhanced Raman nano-spectroscopy, nonlinear photoemission electron microscopy, as well as correlated scanning transmission electron microscopy-electron energy loss spectroscopy measurements targeting prototypical plasmonic nanostructures and constructs. Through selected practical examples from our own laboratories, we examine the information content in multidimensional images recorded by taking advantage of each of the aforementioned techniques. In effect, we illustrate how SPs can be visualized at the ultimate limits of space and time.

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Section: Imaging Localized and Propagating Surface Plasmons With Nonlmentioning

confidence: 99%

Visualizing surface plasmons with photons, photoelectrons, and electrons

El‐Khoury

Abellán

Gong

et al. 2016

Analyst

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“…A multitude of experimental methods have been used to show that the work function of different crystal faces of the same metal can vary over hundreds of meV [28][29][30]. These experimentally observed variations have been corroborated by theoretical studies and ab initio calculations [31,32].…”

mentioning

confidence: 94%

Influence of interface inhomogeneities in thin-film Schottky diodes

Wilson

Zhang

Liu

et al. 2017

Applied Physics Letters

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The scalability of thin-film transistors has been well documented, but there have been very few investigations into of the effects of device scalability in Schottky diodes. Indium-gallium-zinc-oxide (IGZO) Schottky diodes were fabricated with IGZO thicknesses of 50, 150 and 250 nm. Despite the same IGZO-Pt interface and Schottky barrier being formed in all devices, reducing the IGZO thickness caused a dramatic deterioration of the current-voltage characteristics, most notably increasing the reverse current by nearly five orders of magnitude. Furthermore, the forward characteristics display an increase in ideality factor and a reduction in barrier height. The origins of this phenomenon have been elucidated using device simulations. Firstly, when the semiconductor layer is fully depleted, the electric field increases with reducing thickness, leading to an increased diffusion current. However, the effects of diffusion only offer a small contribution to the huge variations in reverse current seen in the experiments. To fully explain this effect the role of inhomogeneities in the Schottky barrier height has been considered. Contributions from lower barrier regions (LBRs) are found to dominate the reverse current. The conduction band minimum below these LBRs is strongly dependent upon thickness and bias, leading to reverse current variations as large as several orders of magnitude. Finally, it is demonstrated that the thickness dependence of the reverse current is exacerbated as the magnitude of the inhomogeneities is increased, and alleviated in the limit where the LBRs are large enough not to be influenced by the adjacent higher barrier regions.In recent years, efforts to realise large-area flexible thinfilm electronics have branched out to incorporate the use of a large variety of materials [1][2][3]. Oxide semiconductors, particularly indium-gallium-zinc-oxide (IGZO), have emerged as leading candidates for application in future display technology [4]. IGZO has demonstrated excellent mobility and transparency [5], and can also be deposited at room temperature, making it compatible with flexible substrates [6]. Initially, most studies were focussed on thin-film transistors (TFTs) [7,8]. However, there is now a growing body of literature on IGZO Schottky diodes [9][10][11][12]. These efforts have led to the realisation of excellent electronic properties such as rectification ratios > 10 7 , barrier heights > 0.9 eV and ideality factors close to unity. Notable achievements include fabricating devices on flexible substrates [9], exhibiting gigahertz operating frequencies [12,13] Unlike TFTs, where scaling phenomena such as the short-channel effect are well documented [19,20], the effects of device scalability on IGZO Schottky diodes has received limited attention. So far, studies of IGZO Schottky diodes have been focused on the forward current, except work regarding the reverse breakdown voltage [21]. * Please address correspondence to A.Song@manchester.ac.uk Reducing the thickness of the IGZO should be beneficial ...

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“…For the same metal, different planes have different workfunction and the atomically rough surface has a smaller workfunction than the atomically smooth surface such as fcc (111). For example, the workfunction of the (110) and (111) surfaces is 4.14 (+0.04 or -0.04) eV and 4.46 (+0.02 or -0.02) eV for Ag [23], 4.48 eV and 4.94 eV for Cu, respectively [24]. We can again see that the plane with a smaller workfunction grows faster (preferentially).…”

Section: Methodsmentioning

confidence: 71%

Silver and Copper Microstructures: The Workfunction’s Effect

Mehmood¹

2017

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Abstract:To understand the growth mechanism of Ag and Cu nanowires we have studied the effect of workfunction on the metal nanowire growth by XRD, SEM and Potentiostat. Under the same potential and overpotential, the metal with a smaller workfunction has a higher current density, i.e. current density for Ag is higher than of Cu nanowires. Likewise metals, the plane with smaller workfunction grows faster than with the larger workfunction, thus the preferential growth plane is (220) for both metals. We argued that the current arises from electrons tunneling from metal surface to hydrated metal and hydrogen ions. The metal with a smaller workfunction has a thinner barrier for tunneling, thus leading to a higher current density. It is found that deposition method have no such effect on the structure of deposited nanowires.

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Work function measurements on (110), (100) and (111) surfaces of silver

Cited by 237 publications

References 15 publications

Visualizing surface plasmons with photons, photoelectrons, and electrons

Visualizing surface plasmons with photons, photoelectrons, and electrons

Influence of interface inhomogeneities in thin-film Schottky diodes

Silver and Copper Microstructures: The Workfunction’s Effect

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