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

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 I_on/I_off 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. A highly flexible high performing thin film transistor array is constructed from a solution-based polyimide substrate with embedded laser-welded silver nanowires, a hybrid organic/inorganic gate insulator, and a multilayer MoS₂ channel. Highest achieved μ_eff and I_on/I_off are 141 cm² V^-1 s^-1 and 5 × 10⁵, respectively, while no apparent degradation under mechanical stress is observed.