Bottom-up synthesis of graphene nanoribbons (GNRs) by surface-assisted polymerization and cyclodehydrogenation of specifically designed precursor monomers has been shown to yield precise edges and doping. Here we use a precursor monomer containing sulfur atoms to fabricate nanostructures on a Au(111) surface at different annealing temperatures. The nanostructures have distinct configurations, varying from sulfur-doped polymers to sulfur-doped chevron-type GNRs (CGNRs) and, finally, pristine graphene nanoribbons with specific edges of periodic five-member carbon rings. Non-contact atomic force microscopy provides clear evidence for the cleavage of C–S bonds and formation of pristine CGNRs at elevated annealing temperatures. First-principles calculations show that the CGNRs exhibit negative differential resistance.

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通过表面辅助聚合和特殊设计的前体单体的环脱氢，自下而上合成石墨烯纳米带（GNR）已显示出精确的边缘和掺杂。在这里，我们使用含有硫原子的前体单体在不同的退火温度下在Au（111）表面上制造纳米结构。纳米结构具有不同的构型，从掺杂硫的聚合物到掺杂硫的人字形GNR（CGNR），最后是具有周期性五元碳环特定边缘的原始石墨烯纳米带。非接触原子力显微镜为高温退火下C–S键的断裂和原始CGNR的形成提供了清晰的证据。第一性原理计算表明，CGNRs表现出负的差分电阻。

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