OFETs with active channels formed of densified layers
The present invention provides apparatus and a method of fabricating the apparatus. The apparatus includes a substrate having a surface and an organic field-effect transistor (OFET) located adjacent the surface of the substrate. The OFET comprising a gate, a channel, a source electrode, and a drain electrode. The channel comprises a densified layer of organic molecules with conjugated multiple bonds, axes of the organic molecules being oriented substantially normal to the surface.
1. An apparatus, comprising,
a substrate having a surface;
an organic field-effect transistor located adjacent said surface of said substrate, said transistor comprising a gate, a channel, a source electrode, and a drain electrode; and
wherein said channel comprises a densified layer of organic molecules with conjugated multiple bonds, axes of said organic molecules being oriented substantially normal to said surface.
2. The apparatus of claim 1 , wherein said densified layer of organic molecules has a surface density of at least about 7 molecules/nm 2 .
3. The apparatus of claim 1 , wherein said densified layer is defined by said organic molecules having an average separation of less than about 3.8 Angstroms.
4. The apparatus of claim 1 , wherein said densified layer is defined by said organic molecules having a uniform orientation that provides a polarization ratio of greater than about 1.
5. The apparatus of claim 4 , wherein said uniform orientation is substantially coincident in a direction of current flow between said source and drain electrodes.
6. The apparatus of claim 1 , wherein said substrate comprises an elastomer, wherein said elastomer has a glass transition temperature (T G ) of less than about 30° C.
7. The apparatus of claim 6 , wherein said elastomer is an alkyl-substituted polysiloxane.
8. The apparatus as recited in claim 6 , wherein said organic molecules have substantially coplanar aromatic groups.
9. The apparatus as recited in claim 1 , wherein said organic molecules are linear organic molecules.
10. The apparatus as recited in claim 1 , wherein said organic molecules are covalently bonded to said surface.
11. The apparatus as recited in claim 1 , wherein said channel has a field effect mobility of at least about 10 −4 cm 2 V −1 s −1.