Inkjet Printed Circuits with 2D Semiconductor Inks for High‐Performance Electronics

Tian Carey,Mario Lanza,Andrew Flewitt,Nicola Gasparini,Luca Anzi,Felice Torrisi,Gwenhivir Wyatt‐Moon,Sivasambu Bohm,Iain Mcculloch,Adrees Arbab,Fei Hui,Andrew Wadsworth,Helen Bristow,Roman Sordan,Jong M Kim

doi:10.1002/aelm.202100112

Abstract

AbstractAir‐stable semiconducting inks suitable for complementary logic are key to create low‐power printed integrated circuits (ICs). High‐performance printable electronic inks with 2D materials have the potential to enable the next generation of high performance low‐cost printed digital electronics. Here, the authors demonstrate air‐stable, low voltage (<5 V) operation of inkjet‐printed n‐type molybdenum disulfide (MoS2), and p‐type indacenodithiophene‐co‐benzothiadiazole (IDT‐BT) field‐effect transistors (FETs), estimating an average switching time of τMoS2 ≈ 4.1 μs for the MoS2 FETs. They achieve this by engineering high‐quality MoS2 and air‐stable IDT‐BT inks suitable for inkjet‐printing complementary pairs of n‐type MoS2 and p‐type IDT‐BT FETs. They then integrate MoS2 and IDT‐BT FETs to realize inkjet‐printed complementary logic inverters with a voltage gain |Av| ≈ 4 when in resistive load configuration and |Av| ≈ 1.4 in complementary configuration. These results represent a key enabling step towards ubiquitous long‐term stable, low‐cost printed digital ICs.

Highlights

Digital integrated circuits (ICs) mainly rely on a metal-oxide-semiconductor (MOS) technology that uses p-type (PMOS logic) or n-type (NMOS logic) field-effect transistors (FETs) to implement mixed signal ICs[1] and logic gates.[2]
The transmission electron microscopy (TEM) agrees with the atomic force microscopy (AFM) data showing a lateral size of ≈ 1 μm while the diffraction pattern indicates the sixfold symmetry that is expected from MoS2 flakes.[36,37]
We demonstrated air-stable and low voltage (< 5 V) inkjet printed n-type MoS2 with a fast switching time of τMoS2 ≈ 4.1 ± 0.4 μs, which is four orders of magnitude faster than state-ofthe art solution processed MoS2 transistors.[22]

Summary

Introduction

Digital integrated circuits (ICs) mainly rely on a metal-oxide-semiconductor (MOS) technology that uses p-type (PMOS logic) or n-type (NMOS logic) field-effect transistors (FETs) to implement mixed signal ICs[1] and logic gates.[2]. Inkjet printed graphene FETs reached μ of up to 95 cm V−1 s−1 and Ion/Ioff ≈ 10, on a surface-modified Si/SiO2 substrate.[21] Fully inkjet-printed dielectrically-gated flexible graphene/hBN FETs reported μ of up to 204 cm V−1 s−1 on polyethylene terephthalate (PET) with Ion/Ioff ≈ 2.5 at low operating voltage (< 5 V) in ambient conditions.[10] These graphene/h-BN FETs enabled inkjet-printed ICs such as memories, logic gates, and CMOS with a gain of only |Av| ≈ 0.1.[10] Current modulation in printed thin films of LPE MoS2, tungsten disulfide (WS2), molybdenum diselenide (MoSe2), and WSe2 on PET has been attempted via electrochemical gating by a liquid electrolyte (LE), achieving Ion/Ioff ≈ 600 and μ ≈ 0.1 cm V−1 s−1 for MoSe2 and WS2 films in vacuum.[22] the absence of printable highly crystalline semiconducting E2D inks able to exhibit field-effect modulation in ambient conditions has impeded the implementation of inkjet printed 2D material FETs suitable for digital ICs.[20,27]. The printed logics achieved |Av| ≈ 4 and |Av| ≈ 1.4 in NMOS and CMOS configurations, respectively

Inks Formulation

Inkjet Printed MoS2 FETs

Conclusion

Experimental Section

Data Availability Statement