Work Function Changes of Azo-Derivatives Adsorbed on a Gold Surface

2014 ◽  
Vol 118 (45) ◽  
pp. 26033-26040 ◽  
Author(s):  
Enrico Benassi ◽  
Stefano Corni
Keyword(s):  
Work Function ◽  
Gold Surface ◽  
Azo Derivatives

Study of adsorption on metals by the contact potential technique

1953 ◽  
Vol 6 (2) ◽  
pp. 109 ◽  
Author(s):  
JR Anderson ◽  
AE Alexander
Keyword(s):  
Ethyl Acetate ◽  
Hysteresis Loop ◽  
Work Function ◽  
Vapour Pressure ◽  
Physical Adsorption ◽  
Surface Preparation ◽  
Gold Surface ◽  
Contact Potential ◽  
Relative Vapour Pressure ◽  
Adsorption Of Water

The change in contact potential between metals due to physical adsorption of water vapour, isopropanol, and ethyl acetate has been studied. The plot of contact potential against relative vapour pressure showed a hysteresis loop, the behaviour varying for different methods of surface preparation. An initial irreversible potential change was always found, due to chemisorption. By studying the dependence of the contact potential on the temperature of one of the metal surfaces it has been possible to determine the change in work function of a gold surface due to physical adsorption.

Hydrogen Detection with Noble Metal-TiO2 Schottky Diodes

2011 ◽  
Vol 495 ◽  
pp. 289-293 ◽  
Author(s):  
Saeedeh Rahbarpour ◽  
Faramarz Hossein-Babaei
Keyword(s):  
Work Function ◽  
Barrier Height ◽  
Noble Metal ◽  
Schottky Diodes ◽  
Gold Surface ◽  
Silver Surface ◽  
Current Increase ◽  
Hydrogen Detection ◽  
Fast Detection ◽  
Metal Interactions

Fast detection of hydrogen at a wide concentration range is desired for many applications. We report detecting hydrogen using Au-TiO2-Ti and Ag-TiO2-Ti diodes. While hydrogen-Au and hydrogen-Ag interactions are very different, at a constant biasing voltage, the measured current in both diodes is highly sensitive to the partial pressure of hydrogen contamination in the surrounding atmosphere. Work function variations were investigated by connecting the I-V specifications to the energy barrier height established at the Au-TiO2 and Ag-TiO2 junctions. Electronic features of the devices were described based on the assumption of two different hydrogen-noble metal interactions: Hydrogen reduces Ag work function by reducing the adsorbed oxygen species from the silver surface, while Au work function is reduced by the same mechanism as well as the direct adsorption of hydrogen species to the gold surface. Both of these mechanisms result in hydrogen detection by Schottky barrier height reduction and current increase.

scholarly journals Engineering of gold surface work function by electrodeposition of spirobifluorene donor–acceptor bipolar systems

2009 ◽  
Vol 10 (7) ◽  
pp. 1307-1313 ◽  
Author(s):  
Philipp Zabel ◽  
Thomas Dittrich ◽  
Yuan-Li Liao ◽  
Chi-Yen Lin ◽  
Ken-Tsung Wong ◽  
...  
Keyword(s):  
Work Function ◽  
Gold Surface ◽  
Surface Work ◽  
Donor Acceptor ◽  
Surface Work Function

Surface reactions observed by photoemission electron microscopy (PEEM)

1992 ◽  
Vol 50 (1) ◽  
pp. 286-287
Author(s):  
H.H. Rotermund
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Work Function ◽  
Chemical Reactions ◽  
Reaction Diffusion ◽  
Dynamic Processes ◽  
Clean Surface ◽  
Crystal Surfaces ◽  
Single Crystal Surfaces ◽  
Photoemission Electron

Chemical reactions at a surface will in most cases show a measurable influence on the work function of the clean surface. This change of the work function δφ can be used to image the local distributions of the investigated reaction,.if one of the reacting partners is adsorbed at the surface in form of islands of sufficient size (Δ>0.2μm). These can than be visualized via a photoemission electron microscope (PEEM). Changes of φ as low as 2 meV give already a change in the total intensity of a PEEM picture. To achieve reasonable contrast for an image several 10 meV of δφ are needed. Dynamic processes as surface diffusion of CO or O on single crystal surfaces as well as reaction / diffusion fronts have been observed in real time and space.

Epitaxial ferroelectric thin films

1994 ◽  
Vol 52 ◽  
pp. 572-573
Author(s):  
S. G. Ghonge ◽  
E. Goo ◽  
R. Ramesh ◽  
R. Haakenaasen ◽  
D. K. Fork
Keyword(s):  
Single Crystal ◽  
Work Function ◽  
Nonvolatile Memory ◽  
Ferroelectric Properties ◽  
Electrical Contact ◽  
Memory Devices ◽  
Ferroelectric Films ◽  
Si Substrates ◽  
Electro Optic ◽  
Wide Range

Microstructure of epitaxial ferroelectric/conductive oxide heterostructures on LaAIO3(LAO) and Si substrates have been studied by conventional and high resolution transmission electron microscopy. The epitaxial films have a wide range of potential applications in areas such as non-volatile memory devices, electro-optic devices and pyroelectric detectors. For applications such as electro-optic devices the films must be single crystal and for applications such as nonvolatile memory devices and pyroelectric devices single crystal films will enhance the performance of the devices. The ferroelectric films studied are Pb(Zr0.2Ti0.8)O3(PLZT), PbTiO3(PT), BiTiO3(BT) and Pb0.9La0.1(Zr0.2Ti0.8)0.975O3(PLZT).Electrical contact to ferroelectric films is commonly made with metals such as Pt. Metals generally have a large difference in work function compared to the work function of the ferroelectric oxides. This results in a Schottky barrier at the interface and the interfacial space charge is believed to responsible for domain pinning and degradation in the ferroelectric properties resulting in phenomenon such as fatigue.

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