Tunneling conjugated polymers

M. Brun, R. Demadrille, P. Rannou, A. Pron, J.P. Travers, and B. Grevin, Multiscale scanning tunneling microscopy study of self-assembly phenomena in two-dimensional polycrystals of pi-conjugated polymers the case of regioregular poly (dioctylbithiophene-alt-fluore-none). Adv. Mater., 16, 2087 (2004). 

ID Nature of Conjugated Polymers and Theories for Tunneling in ID Conductors... 

However, the values for the current that are obtained with the actual device parameters using the Fowler-Nordheim equation are several orders of magnitude higher than the values for the measured current in real devices. This is due to the fact that the I-V characteristics of PLEDs are determined not only by the injection mechanisms but also by the charge transport mechanism in the active polymer layer (see Section V). The discrepancy between the measured and calculated values for the current in the model for field-induced tunneling can be accounted for by a backflow current of the injected charge carriers into the injection contact. This effect then reduces the net device current and seems to be especially important in low mobility conjugated polymers [93]. 

Figure 8.45. Schematic cross section of tunnel diodes fabricated from conjugated polymer/C o composities. (Reproduced by permission of Elsevier Science from ref 58.)...

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