Visualized Dielectric Screening Enhanced Hole‐Mobility in 2D PtSe ₂ for Wireless Communication

Abstract 2D transition metal dichalcogenides (TMDs) are promising candidates for CMOS technology in the post‐Moore era, whereas there is a lack of research on p‐TMDs involved in multifunctional integrated circuits toward ultrathin flexibility, high switching speed, and high frequency communication. The key challenge lies in overcoming the carrier mobility limitations imposed by material quality and metal‐semiconductor‐insulator interfaces. Herein, high‐quality 2D PtSe ₂ enabled transistors with a high hole‐mobility (36.5 cm ² V ⁻¹ s ⁻¹ ) are demonstrated via low‐thermal‐budget synthesis and atomic engineering at the semiconductor‐dielectric interface. By systematic screening the dielectric constant (κ), the optimal κ‐value range for enhancing hole‐dominated transport in synthesized PtSe ₂ is identified. Balancing Coulomb Impurity (CI) scattering and Surface Optical (SO) phonon scattering, the effect‐field mobility of 2D PtSe ₂ on Al ₂ O ₃ dielectric is enhanced by 210% and 400% compared to the devices on HfO ₂ and SiO ₂ , respectively. Importantly, atomic‐resolution electron energy loss spectroscopy (EELS) further visualizes depth‐dependent, distinct domains of two scatterings at the PtSe ₂ ‐Al ₂ O ₃ interface to reveal mechanisms of mobility enhancement. And the competitive interplay between two scatterings in transport properties is observed ≈100 K. Consequently, self‐aligned PtSe ₂ transistors operating ≈0.3 GHz are realized, paving an essential path for future high‐data‐rate communication systems.