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Disorder energetic

The mess caused by dropping sugar reflects the way nature always seeks to maximize disorder. Both examples so far, of dye diffusing in water and sugar causing a mess, demonstrate the achievement of greater disorder. But if we are specific, we should note how it is the energetic disorder that is maximized spontaneously. [Pg.130]

We have already seen the way processes occur with an attendant increase in disorder. We now introduce the concept of entropy. The extent of energetic disorder is given the name entropy (and has the symbol S). A bigger value of S corresponds to a greater extent of energetic disorder. [Pg.131]

We now introduce the second law of thermodynamics a physicochemical process only occurs spontaneously if accompanied by an increase in the entropy S. By corollary, a non-spontaneous process - one that we can force to occur by externally adding energy - would proceed concurrently with a decrease in the energetic disorder. [Pg.131]

We can often think of entropy merely in terms of spatial disorder, like the example of the sugar grains above but the entropy of a substance is properly the extent of energetic disorder. Molecules of hot and cold water in a bath exchange energy in order to maximize the randomness of their energies. [Pg.131]

The second law of thermodynamics says a process occurs spontaneously only when the concomitant energetic disorder increases. We can usually approximate, and talk in terms of disorder alone. [Pg.131]

After their release from solvating this chloride ion, each water molecule has as much energetic disorder as did the whole chloride ion complex. Therefore, we expect a sizeable increase in the entropy of the solvent during crystallization because many water molecules are released. [Pg.138]

As a new criterion for reaction spontaneity, we say AS(totai) must be positive. We must consider the surroundings if we are to understand how the overall extent of energetic disorder increases during a process. [Pg.139]

The heat capacity of a liquid is always greater than the heat capacity of the respective solid because the liquid, having a greater amount of energetic disorder, has a greater entropy according to... [Pg.140]

For materials with small energetic disorder, but large E, the mobility may decrease with increasing fields that was demonstrated first for the molecular glass o-TTA (26a) (p0 = 9.7 x 10 3 cm2/Vs, a = 0.059 eV, E = 2.4), measured at room temperature [71]. [Pg.152]

To analyze the negative field dependence of the mobihty in EHO-OPPE within the Gaussian disorder transport formahsm and to determine the diagonal (energetic) disorder parameter a and the off-diagonal (positional) disorder parameter d, the following relation between the charge mobihty p and the disorder parameters was employed [75] ... [Pg.223]

Off-diagonal (positional) disorder parameter. Diagonal (energetic) disorder parameter at 20 °G. [Pg.224]

In an extended version of the hopping concept, positional ( off-diagonal ) disorder in addition to energetic ( diagonal ) disorder has been introduced [54,63]. The simplest ansatz was to incorporate this by allowing the electronic overlap parameter 2ya to vary statistically. Operationally, one splits this parameter into two site contributions, each taken from a Gaussian probability density, and defines a positional disorder parameter I, in addition to the energetic disorder parameter cr. [Pg.19]

Schein LB, Tyutnev A (2008) The contribution of energetic disorder to charge transport in molecularly doped polymers. J Phys Chem C 112 7295... [Pg.59]

Van Mensfoort 8LM, Vulto 8IE, Janssen RAJ, Coehoom R (2008) Hole transport in polyfluorene-based sandwich-type devices quantitative analysis of the role of energetic disorder. Phys Rev B 78 085208... [Pg.60]

Blakesley JC, Clubb HS, Greenham NC (2010) Temperature-dependent electron and hole transport in disordered semiconducting polymers analysis of energetic disorder. Phys Rev B 81 045210... [Pg.61]


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Charge energetic disorder

Energetic and Positional Disorder

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