Complementary Two-input NAND Gates with Low-voltage-operating Organic Transistors on Plastic Substrates

Abstract

We fabricated two-input NAND gates composed of p-channel pentacene and n-channel C60 transistors. The logic devices were prepared on flexible polymer substrates through a shadow mask process. Correct NAND logic functionality was demonstrated at a wide voltage range of 2–7 V. From voltage transfer characteristics of the NAND gates, we obtained impressive signal gains up to 120 and large noise margins in the given voltage range.

Air-Stable, Hysteresis-Free Organic Complementary Inverters Produced by the Neutral Cluster Beam Deposition Method

“…2 Organic complementary metal oxide semiconductor (CMOS) inverters are the most basic circuit element in CMOS technology and are considered to be the key building block of logic architectures which include NOR, NAND, SRAM, and ring oscillators. 3,4 In principle, structurally simple inverters can be produced utilizing ambipolar transistors. 5,6 In cases of such ambipolar OFETs, however, the validity remains controversial, since either hole or electron charge transport occurs at all gate biases, resulting in unwanted incomplete switching-off and high power consumption.…”

“…Organic complementary metal oxide semiconductor (CMOS) inverters are the most basic circuit element in CMOS technology and are considered to be the key building block of logic architectures which include NOR, NAND, SRAM, and ring oscillators. , In principle, structurally simple inverters can be produced utilizing ambipolar transistors. , In cases of such ambipolar OFETs, however, the validity remains controversial, since either hole or electron charge transport occurs at all gate biases, resulting in unwanted incomplete switching-off and high power consumption. In contrast, although there is a physical separation between the p- and n-type transistors, an efficient and convenient CMOS architecture would integrate two unipolar OFETs on the same substrate. − In adopting such a device configuration, there exist a few drawbacks that restrict application to commercial organic circuits: balanced carrier mobilities ; air stability ; hysteresis .…”

Improvement in Mobility and Stability of n-Type Organic Field-Effect Transistors with a Hole Transporting Interfacial Layer

“…1,2) OFETs, fabricated using different combinations of n-and p-type organic semiconductors, can be used in complementary circuits as well as conventional silicon devices. 3,4) Thus far, the synthesis of various types of organic semiconductor materials have been reported; however, only a few types of n-type organic semiconductor materials exist, and their performance is generally worse than that of p-type materials. 5) Chua and et al pointed out that the reason for this difference in performance is essentially attributed to the surface electron traps of the gate insulator; if these electron traps can be completely eliminated, all organic semiconductors would have a potential to operate in the n-type mode.…”

Low-voltage-operating organic complementary circuits based on pentacene and C60 transistors

“…We have recently demonstrated high performance n-channel organic TFTs with field-effect mobility of~1 cm 2 /V s at an operating voltage of 5 V using an amorphous phase C 60 films [4], comparable to those of high performance p-channel pentacene TFTs with self-assembled monolayers (SAM) [5] or high dielectric constant (high-k) gate insulators [6,7]. The high mobility of n-channel TFTs yields complementary inverters and inverted-AND gates with fairly balanced operations in static characteristics [8,9].…”