Modulation Doping via a 2d Atomic Crystalline Acceptor

Abstract

Two-dimensional (2d) nano-electronics, plasmonics, and emergent phases require clean and local charge control, calling for layered, crystalline acceptors or donors. Our Raman, photovoltage, and electrical conductance measurements combined with \textit{ab initio} calculations establish the large work function and narrow bands of $\hat{I}\pm$-RuCl${}_3$ enable modulation doping of exfoliated, chemical vapor deposition (CVD), and molecular beam epitaxy (MBE) materials. Short-ranged lateral doping ($\le 65\text{nm}$) and high homogeneity are achieved in proximate materials with a single layer of \arucl. This leads to the highest monolayer graphene (mlg) mobilities ($4,900{\text{cm}}^2/\text{Vs}$) at these high hole densities ($3\times 10^{13}{\text{cm}}^{-2}$); and yields larger charge transfer to bilayer graphene (blg) ($6\times 10^{13}{\text{cm}}^{-2}$). We further demonstrate proof of principle optical sensing, control via twist angle, and charge transfer through hexagonal boron nitride (hBN).