Electrostatic Doping of 2D Semiconductors Using Charged Dielectric Thin Films.

Abstract

Doping two-dimensional (2D) semiconductors without direct chemical or structural modification of the channel remains a central challenge for device integration. Here we demonstrate an electrostatic doping strategy on monolayer MoS₂ based on embedding fixed charge in engineered dielectric stacks, enabling carrier modulation in the absence of volatile external bias. By comparing different dielectric architectures, we show that effective electrostatic doping is governed by the defect landscape of the capping dielectrics and their interface with the 2D channel. A self-consistent electrostatic model reveals that interface states control the partitioning of the dielectric embedded charge between carriers trapped in defects or free for conduction in the channel, posing limits to the effectiveness of electrostatic coupling. This work establishes electrostatic doping as a viable strategy for carrier modulation in 2D semiconductors and identifies dielectric defect engineering as central to its implementation.