Controlled atomic patterning is an attractive tool to fine tune properties of graphitic lattice. Several O-functionalized derivatives of graphitic lattice have been widely studied, e.g., graphene oxide, reduced graphene oxide, and functionalized carbon nanotubes. A controlled patterning of chemisorbed O atom is highly desired to fine tune physical and chemical properties, e.g., bandgap, conductivity, hydrophilicity, reactivity, etc. However, patterning of chemisorbed O on the graphitic lattice at the nanometer scale has not been reported. In this study, using scanning tunneling microscopy (STM), we manipulate chemisorbed O (epoxy) on the graphitic lattice, on demand, on the desired atom, on an atom-by-atom basis. We show that chemisorbed O can be desorbed when an energy exceeding the energy barrier for desorption (∼1.3 eV) is supplied as the bias voltage for imaging. This resulted in pristine, defect-free, and clean graphitic lattice at the site of desorption. Nanometer-scale patterns with resolution of oxygen-free regions surrounded by oxygen-rich regions could be achieved by scanning a pre-defined area. A distinct imaging effects was observed with low and high bias voltage-based scanning which is attributed to the local density of states of the O-functionalized graphitic lattice. Overall, the novel atomic-oxygen nanolithography of graphitic surface opens pathways for studying physicochemical properties of the functional groups in nanometer-scale confinement.

中文翻译：

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石墨晶格上化学吸附氧原子的纳米栅栏结构的纳米光刻


受控原子图案化是微调石墨晶格特性的一种有吸引力的工具。石墨晶格的几种O-官能化衍生物已被广泛研究，例如氧化石墨烯、还原氧化石墨烯和官能化碳纳米管。非常需要化学吸附 O 原子的受控图案化来微调物理和化学性质，例如带隙、电导率、亲水性、反应性等。然而，化学吸附 O 在石墨晶格上纳米尺度的图案化尚未见报道。在这项研究中，我们使用扫描隧道显微镜 (STM)，根据需要在所需的原子上逐个原子地操纵石墨晶格上化学吸附的 O（环氧树脂）。我们表明，当提供超过解吸能垒（~1.3 eV）的能量作为成像偏置电压时，化学吸附的 O 可以被解吸。这在解吸部位产生了原始、无缺陷且干净的石墨晶格。通过扫描预定义区域可以实现具有被富氧区域包围的无氧区域分辨率的纳米级图案。通过基于低偏压和高偏压的扫描观察到明显的成像效果，这归因于O-功能化石墨晶格的局部态密度。总体而言，石墨表面的新型原子氧纳米光刻技术为研究纳米级限制中官能团的物理化学性质开辟了途径。