Achieving high-quality single-atom nitrogen doping of graphene/SiC(0001) by ion implantation and subsequent thermal stabilization.

Telychko, Mykola; Mutombo, Pingo; Ondráček, Martin; Hapala, Prokop; Bocquet, François C; Kolorenč, Jindřich; Vondráček, Martin; Jelínek, Pavel et al. · ACS Nano · 2014

basic_science · Level V

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Abstract

We report a straightforward method to produce high-quality nitrogen-doped graphene on SiC(0001) using direct nitrogen ion implantation and subsequent stabilization at temperatures above 1300 K. We demonstrate that double defects, which comprise two nitrogen defects in a second-nearest-neighbor (meta) configuration, can be formed in a controlled way by adjusting the duration of bombardment. Two types of atomic contrast of single N defects are identified in scanning tunneling microscopy. We attribute the origin of these two contrasts to different tip structures by means of STM simulations. The characteristic dip observed over N defects is explained in terms of the destructive quantum interference.