Organic semiconductor electronic devices

In a solar cell device with well-separated electron and hole channels, the MR value reduces dramatically showing clearly that the bipolaronic picture can not account for the magnetic field dependent transport properties in organic semiconductor based devices. 

Whether SAMs will ever be incorporated in commercial devices is not yet clear, but quite recently a major step was achieved by Baldo et al. who produced a photosynthetic device consisting of a SAM of photosystem I isolated from spinach chloroplasts stabilised with surfactant peptides and coated with a protective organic semiconductor. This device, which has an internal quantiun efficiency of 12%, was stable for several weeks under ambient conditions [240]. Therefore, we conclude that functional SAMs have a good prospect of being implemented in a variety of electronic devices in the future. 

The simplest and most widely used model to explain the response of organic photovoltaic devices under illumination is a metal-insulaior-metal (MIM) tunnel diode [55] with asymmetrical work-function metal electrodes (see Fig. 15-10). In forward bias, holes from the high work-function metal and electrons from the low work-function metal are injected into the organic semiconductor thin film. Because of the asymmetry of the work-functions for the two different metals, forward bias currents are orders of magnitude larger than reverse bias currents at low voltages. The expansion of the current transport model described above to a carrier generation term was not taken into account until now. 

Organic semiconductors are becoming increasingly important in the fabrication of electronic devices. For electron transport, metal complex pigments, such as hexa-deca-fluoro copper phthalocyanine (76), are showing potential.79... 

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