Atomic-scale characterization of nitrogen-doped graphite: Effects of dopant nitrogen on the local electronic structure of the surrounding carbon atoms
Atomic-scale characterization of nitrogen-doped graphite: Effects of dopant nitrogen on the local electronic structure of the surrounding carbon atoms
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DOI：
10.1103/physrevb.86.035436
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发表时间：
2012-07-23
影响因子：
3.7
通讯作者：
Nakamura, Junji
中科院分区：
文献类型：
--
作者：
Kondo, Takahiro;Casolo, Simone;Nakamura, Junji
我们报告的局部原子和电子结构的氮掺杂石墨表面的扫描隧道显微镜，扫描隧道光谱，x射线光电子能谱，和第一性原理计算。通过氮离子轰击和热退火制备了掺氮石墨。两种类型的氮物种被确定在原子水平上：吡啶-N（N键合到两个C最近的邻居）和石墨-N（N键合到三个C最近的邻居）。在吡啶-N和石墨-N物种周围的碳原子的费米能级附近的被占据和未被占据的区域中，分别发现了局域π态的不同电子态。这些状态的起源进行了讨论的基础上的实验结果和理论模拟。
We report on the local atomic and electronic structures of a nitrogen-doped graphite surface by scanning tunneling microscopy, scanning tunneling spectroscopy, x-ray photoelectron spectroscopy, and first-principles calculations. The nitrogen-doped graphite was prepared by nitrogen ion bombardment followed by thermal annealing. Two types of nitrogen species were identified at the atomic level: pyridinic-N (N bonded to two C nearest neighbors) and graphitic-N (N bonded to three C nearest neighbors). Distinct electronic states of localized pi states were found to appear in the occupied and unoccupied regions near the Fermi level at the carbon atoms around pyridinic-N and graphitic-N species, respectively. The origin of these states is discussed based on experimental results and theoretical simulations.