P-type and n-type top-gate carbon nanotube thin-film transistors (TFTs) can be selectively and simultaneously fabricated on the same polyethylene terephthalate (PET) substrate by tuning the types of polymer-sorted semiconducting single-walled carbon nanotube (sc-SWCNT) inks, along with low temperature growth of HfO thin films as shared dielectric layers. Both the p-type and n-type TFTs show good electrical properties with on/off ratio of ≈10 , mobility of ≈15 cm V s , and small hysteresis. Complementary metal oxide semiconductor (CMOS)-like logic gates and circuits based on as-prepared p-type and n-type TFTs have been achieved. Flexible CMOS-like inverters exhibit large noise margin of 84% at low voltage (1/2 V = 1.5 V) and maximum voltage gain of 30 at V of 1.5 V and low power consumption of 0.1 μW. Both of the noise margin and voltage gain are one of the best values reported for flexible CMOS-like inverters at V less than 2 V. The printed CMOS-like inverters work well at 10 kHz with 2% voltage loss and delay time of ≈15 μs. A 3-stage ring oscillator has also been demonstrated on PET substrates and the oscillation frequency of 3.3 kHz at V of 1 V is achieved.

External load dependent degradation behavior of P3HT:PC61BM solar cells is demonstrated, which can be successfully suppressed by blending with an exciton quencher of PC61BM.

The fabrication of printed high-performance and environmentally stable n-type single-walled carbon nanotube (SWCNT) transistors and their integration into complementary (i.e., complementary metal-oxide-semiconductor, CMOS) circuits are widely recognized as key to achieving the full potential of carbon nanotube electronics. Here, we report a simple, efficient, and robust method to convert the polarity of SWCNT thin-film transistors (TFTs) using cheap and readily available ethanolamine as an electron doping agent. Printed p-type bottom-gate SWCNT TFTs can be selectively converted into n-type by deposition of ethanolamine inks on the transistor active region via aerosol jet printing. Resulted n-type TFTs show excellent electrical properties with an on/off ratio of 10, effective mobility up to 30 cm V s, small hysteresis, and small subthreshold swing (90-140 mV dec), which are superior compared to the original p-type SWCNT devices. The n-type SWCNT TFTs also show good stability in air, and any deterioration of performance due to shelf storage can be fully recovered by a short low-temperature annealing. The easy polarity conversion process allows construction of CMOS circuitry. As an example, CMOS inverters were fabricated using printed p-type and n-type TFTs and exhibited a large noise margin (50 and 103% of 1/2 V = 1 V) and a voltage gain as high as 30 (at V = 1 V). Additionally, the CMOS inverters show full rail-to-rail output voltage swing and low power dissipation (0.1 μW at V = 1 V). The new method paves the way to construct fully functional complex CMOS circuitry by printed TFTs.