Large-scale flexible and transparent electronics based on monolayer molybdenum disulfide field-effect transistors

Atomically thin molybdenum disulfide (MoS₂) is a promising semiconductor material for integrated flexible electronics due to its excellent mechanical, optical and electronic properties. However, the fabrication of large-scale MoS₂-based flexible integrated circuits with high device density and performance remains a challenge. Here, we report the fabrication of transparent MoS₂-based transistors and logic circuits on flexible substrates using four-inch wafer-scale MoS₂ monolayers. Our approach uses a modified chemical vapour deposition process to grow wafer-scale monolayers with large grain sizes and gold/titanium/gold electrodes to create a contact resistance as low as 2.9 kΩ μm⁻¹. The field-effect transistors are fabricated with a high device density (1,518 transistors per cm²) and yield (97%), and exhibit high on/off ratios (10¹⁰), current densities (~35 μA μm⁻¹), mobilities (~55 cm² V⁻¹ s⁻¹) and flexibility. We also use the approach to create various flexible integrated logic circuits: inverters, NOR gates, NAND gates, AND gates, static random access memories and five-stage ring oscillators.