|Charge transport in Organic Field-Effect Transistors
Physics and Astronomy
|Vitaly Podzorov, Rutgers University
4:30pm Physics Lecture Hall
Organic semiconductors have a great promise for modern technology. A variety of electronic devices, such as organic field-effect transistors (OFETs), light-emitting diodes (OLEDs), solar cells and organic memory cells have been demonstrated. Recently, some of these technologies have become commercially viable. Despite the rapid progress in the engineering of organic semiconductor devices, understanding of fundamental aspects of the charge transport in these devices is still lacking. One of the reasons for this is that majority of applications deals with amorphous or polycrystalline organic materials, in which the charge conduction is dominated by defects.
In order to address the intrinsic conduction mechanisms in organic semiconductors, pure and highly ordered systems should be studied. Recently, the organic field-effect transistors (OFETs) have been fabricated on organic molecular crystals with the innovative techniques that preserve the high quality of pristine single-crystal surfaces [1,2]. The single-crystal OFETs provide a unique opportunity for addressing the electronic properties of organic semiconductors not dominated by disorder and determined solely by the physics of defect-free organic material. For example, it is demonstrated that the intrinsic transport with a remarkably high for organic semiconductor mobility of holes ~20 cm2/Vs can be achieved in these devices . Other signatures of the intrinsic transport are the anisotropy of the carrier mobility with cooling. These and various other aspects of the transport and optical properties of organic field-effect transistors will be discussed.
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 V. C. Sundar et al., Science 303, 1644 (2004).
 V. Podzorov et al., Phys. Rev. Lett. 93, 086602 (2004).