High‐Performance Flexible Multilayer MoS₂ Transistors on Solution‐Based Polyimide Substrates

Abstract

Transition metal dichalcogenides (TMDs) layers of molecular thickness, in particular molybdenum disulfide (MoS2), become increasingly important as active elements for mechanically flexible/stretchable electronics owing to their relatively high carrier mobility, wide bandgap, and mechanical flexibility. Although the superior electronic properties of TMD transistors are usually integrated into rigid silicon wafers or glass substrates, the achievement of similar device performance on flexible substrates remains quite a challenge. The present work successfully addresses this challenge by a novel process architecture consisting of a solution‐based polyimide (PI) flexible substrate in which laser‐welded silver nanowires are embedded, a hybrid organic/inorganic gate insulator, and multilayers of MoS2. Transistors fabricated according to this process scheme have decent properties: a field‐effect‐mobility as high as 141 cm2 V−1 s−1 and an Ion/Ioff ratio as high as 5 × 105. Furthermore, no apparent degradation in the device properties is observed under systematic cyclic bending tests with bending radii of 10 and 5 mm. Overall electrical and mechanical results provide potentially important applications in the fabrication of versatile areas of flexible integrated circuitry.

2D MoS2 Neuromorphic Devices for Brain‐Like Computational Systems

“…Compared to zero‐band‐gap graphene, MoS 2 is recently considered as one of the most promising 2D materials for replacing the widely explored 2D graphene, because it is a semiconducting, 2D layered transition‐metal dichalcogenide, with a band gap changing from 1.2 eV in the bulk to 1.8 eV in monolayers . With these intriguing electronic and optical properties, and special atomically scalable structure advantages, the 2D MoS 2 ‐based devices exhibit high promise for many state‐of‐the‐art electronic applications, such as photovoltaic solar cells, flexible electronics, advanced ultrasmall transistors, integrated circuits, etc. Recently, we note that Arnold et al have reported an interesting work to mimic neurotransmitter release by using interface trapping/detrapping in MoS 2 transistors .…”

Flexible Device Applications of 2D Semiconductors

“…By using conventional solid‐state high‐k dielectrics such as HfO 2 on flexible substrates, MoS 2 transistors achieved high ON/OFF ratios, more than 10 7 , and low field mobilities of 30 cm 2 V −1 s −1 , with bending radii down to 1 mm . Recent work successfully used a solution‐based polyimide (PI) flexible substrate in which laser‐welded silver nanowires are embedded, together with a hybrid organic/inorganic gate insulator and multilayers of MoS 2 , resulting in transistors that have field‐effect‐mobilities as high as 141 cm 2 V −1 s −1 and stable performance after 1000 bending cycles, as shown in Figure d,e …”

“…j) Analysis of mechanical robustness of flexible BP transistor with normalized extrinsic f T measured under uniaxial tensile strain up to 1.5%. a), d), e) Reproduced with permission . Copyright 2016, Wiley.…”

Enhanced Quality of Wafer‐Scale MoS2 Films by a Capping Layer Annealing Process

“…The 2D MoS 2 is one of the most promising semiconductors for next generation electronics due to its tunable bandgap, favorable electronic mobility, excellent optoelectronic properties, and good thermal and chemical and mechanical stabilities . Scalable fabrication of 2D films is the precondition for manufacturing of post‐ Moore's law large‐scale integrated devices.…”