Introduction

Dopant Segregation in Polycrystalline Monolayer Graphene

“…14,15 These processes typically lead to the aggregation of dopants at the grain boundary with a length scale of a few lattice constants. [1][2][3][4][5][6][7][8][9]11,12 Recently, it has become possible to create large-area, true 2D (monolayer) materials by chemical vapor deposition (CVD) techniques. When grown by CVD, all of these materials grow as a patchwork quilt of microcrystalline grains separated by edges and grain boundaries.…”

“…Doping, alloying, and functionalization are common strategies by which the electronic properties of materials can be tuned. In three-dimensional (3D) polycrystalline materials such as metals, ceramics, , and semiconductors, − atomic impurities, and dopants are known to migrate toward surfaces and grain boundaries during high-temperature annealing processes, resulting in an inhomogeneous modification of electronic and structural properties of the material. Such chemical segregation is of great practical importance in applications as diverse as structural steels, electronics, ,,, and electrochemical cells .…”

“…First, elevated temperatures used during annealing leads to enhanced diffusion, allowing foreign atoms to reach the grain boundary . Second, electronic interactions between hydrogenic states of the dopant atom and the boundary states leads to binding of the dopant at the boundary. , These processes typically lead to the aggregation of dopants at the grain boundary with a length scale of a few lattice constants. − ,, …”