Interface dipole layer, role

Role of the Interface Dipole Layer Its Impact on the Energy Level Alignment... 

If the CNL of the organic layer is higher than the metal work function, electrons will be transferred from the organic material to the metal, thus giving rise to an interface dipole. Like in the case of the Bardeen model, the CNL plays the role of an effective Fermi level at the interface. 

Interfacial water molecules play important roles in many physical, chemical and biological processes. A molecular-level understanding of the structural arrangement of water molecules at electrode/electrolyte solution interfaces is one of the most important issues in electrochemistry. The presence of oriented water molecules, induced by interactions between water dipoles and electrode and by the strong electric field within the double layer has been proposed [39-41]. It has also been proposed that water molecules are present at electrode surfaces in the form of clusters [42, 43]. Despite the numerous studies on the structure of water at metal electrode surfaces using various techniques such as surface enhanced Raman spectroscopy [44, 45], surface infrared spectroscopy [46, 47[, surface enhanced infrared spectroscopy [7, 8] and X-ray diffraction [48, 49[, the exact nature of the structure of water at an electrode/solution interface is still not fully understood. 

Since the metal can be treated as a nearly perfect conductor, C is high compared with C, and cannot influence the value of the measured doublelayer capacitance. The role of the metal in the double layer structure was discussed by Rice, who suggested that the distribution of electrons inside the metal decides the properties of the double-layer. This concept was later used to describe double-layer properties at the semiconductor/electrolyte interface. As shown later, the electron density on the metal side of the interface can be changed under the influence of charged solution species (dipoles, ions). ... 

In the second step the charge arrives at the internal phase passing through the interface. The associated potential is known as the surface potential jump (also called surface potential, surface electrical potential, etc.). It is determined by dipoles aligned at the interface and by surface charges. It is not identical with the Volta potential difference (also sometimes called the surface potential) that has so far been used for the description of the electrical double layer. For the treatment of the electrical double layer, dipoles did not play a role. In particular in water, however, the aligned water molecules contribute substantially to the surface potential jump x- The Galvani potential, Volta potential, and surface potential jump are related by... 

The above result may raise questions, because the properties of adsorbed monolayers at charged interfaces should be governed by the long-range coulombic interactions. However, it can be easily explained if we take into account that, when we adopt an adsorption mechanism like that represented by Eq. (2), in fact, we model the adsorbed layer as a mixture of adsorbate A molecules and solvent clusters Sa with dimensions equivalent to A. That is, the adsorbed layer consists of species with dimensions greater than 0.25 nm and therefore the (hstance of the closest approach between two adsorbed dipoles cannot fall below 0.5 - 0.6 nm. Thus when we model the adsorbed layer as a mixture of adsorbate A molecules and solvent clusters Sa, the coulombic interactions stop to play the dominant role regarding the properties of this layer. This result is independent of whether we have polarizable or non-polarizable adsorbed molecules and, in fact, verifies the use of... 

In the presence of a polar solvent molecule such as water, considerable attention has been focused on the role of the solvent. Since the dipole moment is free to rotate in the presence of an electric field, it is reasonable that in a layer of water close to the interface there will be a net dipolar orientation and the water will not... 

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