Positive holes transport model

The minimalist model which mimics the essential features derived by the computational studies on realistic systems is made by a one dimensional stack of planar conjugated molecules (Fig. 11), with one molecular orbital per molecule (for example the HOMO in case of hole transport). Each molecule j, associated with the orbital j), has mass m and can be displaced transversally by a length uj from its equilibrium position around which it oscillates with frequency to. The transfer integral T between the consecutive orbitals j) and y - -1) is modulated linearly by the term aa uj+i - uj) with a the electron-phonon coupling constant. The semiclassical Hamiltonian for this system reads... 

The resulting positive TMSi-ion has a much lower mobility (see Section 3.4). The transport of the hole in IXe can be rationalized by the model of the small polaron (see Section 7.3). 

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