Heterojunction FETs

The field-effect mobilities of printed plastic transistors are slightly higher (about two times) when measured in air compared to under vacuum (10 or 10 Torr) [89]. Spin-coated films tend to have lower mobility than cast or printed films possibly because the latter films have better ordering resulting from slower solvent evaporation and consequent slower crystal growth. 

Figore 22. Schematic energy level alignment for p-channel and n-channel operation of a heterojunction FET with a-6T and Ceo active layers. Reprinted with permission from Ref. 97. Copyright AAAS. 

The characteristics of the device under p-channel operation are similar to those of TFTs with only oi-6T active layers. The field-effect mobility is 4 x 10 cm and the threshold voltage is 0 V. The devices under n-channel opera- 

9 Oligo- and Poly thiophene Field Effect Transistors Oligo- and poly thiophene field effect 

The authors thank A. Alam, J. Laquindanum, R. A. Laudise, A. J. Lovinger, T. Siegrist, and L. Torsi for helpful assistance. 

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Figure 23. Current-voltage characteristics of an a-6T/C ) heterojunction FET operating as (a) a p-channel FET with negative Fos and Fds. and (b) operating as an n-channel FET with positive Kgs and Fds- In the n-channel mode of operation there are hole currents flowing in the a-6T layer for Fds > Fgs and are shown by dotted lines. Reprinted with permission from Ref. 97. Copyright 1995 AAAS.

Figure 24. Electron concentration in C ) in an a-6T/C6o heterojunction FET. The legends refer to the distance from the a-6T/Cgo inerface. Reprinted with permission from Ref. 23. Copjnight 1997 IEEE.

Yano, M., Koike, K., Sasa, S. and Inoue, M. (2006) ZnO/ZnMgO heterojunction FETs, in Zinc Oxide Bulk, Thin Films and Nanostructures Processing, Properties and Applications (eds C. Jagadish and S.J. Pearton), Elsevier, Oxford. 

See also Field effect transistors (FETs) Heterojunction insulated gate FETs (HIGFETs), 22 164. See also Field effect transistors (FETs) Heterojunction photodiode arrays,... 

Field-effect transistors (FETs) Heterojunction bipolar transistors (HBTs) High electron mobility transistors (HEMTs) Metal oxide semiconductor FETs (MOSFETs) Single-electron transistors (SETs) Single-heterojunction HBTs (SH-HBTs) Thin-film transistors (TFTs) hydrogenated amorphous silicon in, 22 135... 

Another example of all-polymer bulk heterojunction bipolar FETs was demonstrated recently by Szendrei et al. [15]. The limited number of polymer blend bipolar FETs is due to the scarcity of high-performing n-type polymers. The recent... 

X 10 cm (V s ) at Vds= 30 V. These mobilities are the highest balanced mobilities reported so far for solution processed all polymer bulk heterojunction bipolar FETs. The balanced FET mobilities indicate the presence of sufficient percolation pathways for both charge carriers in these polymer blends. 

Electrical Metal oxide conductivity Organic conductivity Electrolytic conductivity Heterojunction conductivity (Schottky diode, FET, MOS) Work function Electric permittivity (capacitance)... 

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