Laser Direct Writing Process for Making Electrodes and High-k Sol-Gel ZrO₂ for Boosting Performances of MoS₂ Transistors

A series of two-dimensional (2D) transition metal dichalcogenides (TMDCs), including molybdenum disulfide (MoS₂), can be attractive materials for photonic and electronic applications due to their exceptional properties. Among these unique properties, high mobility of 2D TMDCs enables realization of high-performance nanoelectronics based on a thin film transistor (TFT) platform. In this contribution, we report highly enhanced field effect mobility (μ_eff = 50.1 cm²/(V s), ∼2.5 times) of MoS₂ TFTs through the sol-gel processed high-k ZrO₂ (∼22.0) insulator, compared to those of typical MoS₂/SiO₂/Si structures (μ_eff = 19.4 cm²/(V s)) because a high-k dielectric layer can suppress Coulomb electron scattering and reduce interface trap concentration. Additionally, in order to avoid costly conventional mask based photolithography and define the patterns, we employ a simple laser direct writing (LDW) process. This process allows precise and flexible control with reasonable resolution (up to ∼10 nm), depending on the system, and enables fabrication of arbitrarily patterned devices. Taking advantage of continuing developments in laser technology offers a substantial cost decrease, and LDW may emerge as a promising technology.