Janus Electronic Devices with Ultrathin High-κ Gate Dielectric Directly Integrated on 1T′-MoTe₂

Integrating high-quality dielectrics with two-dimensional (2D) transition metal chalcogenides (TMDCs) is crucial for high-performance electronics. However, the lack of dangling bonds on 2D material surfaces complicates direct dielectric deposition. We propose using atomic layer deposition (ALD) to integrate ultrathin high-κ dielectric directly on 1T'-MoTe₂ surfaces, facilitating the creation of high-performance back-gated field-effect transistors (FETs). Exploiting 1T'-MoTe₂'s natural oxidation in ambient conditions, we directly deposit dense and uniform HfO₂ dielectric films below 5 nm, achieving an equivalent oxide thickness (EOT) of 0.97 nm. The resulting back-gate transistors, with a monolayer MoSSe on HfO₂/1T'-MoTe₂, show a current on/off ratio over 10⁵ and operate at low voltages (<1 V), indicating high gating efficiency and a charge carrier mobility of 2.93 cm²V^-1s^-1. Additionally, we demonstrate a 6 × 5 bottom-gated array of MoSSe transistors using all-1T'-MoTe₂ electrodes, achieving an 86.7% sample yield. Our approach also enables the creation of various integrated logic circuits such as inverters, NAND, and NOR gates. This research offers a feasible method for integrating high-κ dielectric films using industrially compatible ALD processes, providing excellent thickness control, uniformity, and scalability for 2D electronic devices.