Ambipolar and Complementary Inverter

As already mentioned, there was the suggestion of using ambipolar FETs to realise complementary-like organic integrated circuits [3, 10, 17, 66]. Here we investigate ambipolar inverters consisting of mixed-layer ambipolar FETs and compare their characteristics to a complementary inverter made of discrete p- and n-channel transistors from neat materials. 

1 3 (b) and a complementary inverter (c) consisting of a neat Cgo and a neat CuPc transistor. The driving voltage is Fdd = 90 V. Transfer characteristics 

For a better understanding of inverter characteristics we performed numerical simulations based on the analytical model of Schmechel et al. [13] for both ambipolar and complementary inverters. The output voltage as well as the ciu-rent dissipation was calculated to demonstrate the differences between ambipolar and complementary inverters and the influence of device parameters like mobility and threshold voltage. 

Brabec, V. Dyakonov, J. Paris , and N. S. Sariciftci, Organic Photo-voltaics (Springer Verlag, 2003). 

Sullivan, S. Heutz, S. M. Schultes, and T. S. Jones, Appl. Phys. Lett. 

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Figure 17.14 Simulations of ambipolar and complementary inverter transfer characteristics and current dissipation with (a) symmetric mobility and threshold voltage for p- and n-channel in comparison with (b) asymmetric mobilities and (c) asymmetric threshold voltages.

Figure 17.12 (a) Electrical circuit for an ambipolar inverter, (b) The two operation regimes (positive and negative supply voltage) for ambipolar and complementary inverters. 

An ambipolar charge transport was observed in transistors based on HD-PPTV. In contrast, only a hole transport mechanism was observed in HD-PPPV. Field-effect transistors that were fabricated from HD-PPTV showed hole and electron mobilities of 0.2 and 0.03 cm V s Integration of the ambipolar HD-PPTV transistors into complementary inverters showed sharp switching characteristics with voltage gains up to 27. 

Anthopoulos, T.D., de Leeuw, D.M., Cantatore, E., Setayesh, S., Meijer, E.J., Tanase, C., Hummelen, J.C. and Blom, P.W.M., Organic complementary-hke inverters employing methanofullerene-based ambipolar field-effect transistors, Appl. Phys. Lett., 85, 4205 207, 2004. 

Figure 16.7 (a) Transfer characteristics of an as-spun PSSS-CIO ambipolar FET with channel length (L) of 40 (im and channel width (W) of 2 cm. The hole and electron mobilities for this device are both 0.026cm (V s ). (b) The transfer characteristic and the corresponding gain (in absolute value) of a complementary-like inverter comprises two identical as-spun PSSS-CIO TC/BC ambipolar FETs. The inset shows... 

Fig. 3.4 a Transfer and b output characteristics of PCII2Se devices fabricated and tested in ambient (L = 50 pm, W = 1 mm, C = 3.7 nF cm ). c Schematic diagram of an inverter device consisted of two connected TG/BC ambipolar transistors, d The VTC characteristic and gain of a complementary-like inverter fabricated with PCII2Se undta- ambient condition (Vdd = 100 V, L = 50 pm, W=4 mm), e Time-dependent decay of device performance of PCIIlSe under ambient condition... 

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