Tuning the morphology of chevron-type graphene nanoribbons by choice of annealing temperature
chevron-type graphene nanoribbon, C-S bond cleavage, negative differential resistance, scanning tunneling microscopy (STM), noncontact atomic force microscopy (NC-AFM), first-principles calculations
ABSTRACT 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.
Tsinghua University Press
Yun Cao,Jing Qi,Yan-Fang Zhang,Li Huang,Qi Zheng,Xiao Lin,Zhihai Cheng,Yu-Yang Zhang,Xinliang Feng,Shixuan Du,Sokrates T. Pantelides,Hong-Jun Gao, Tuning the morphology of chevron-type graphene nanoribbons by choice of annealing temperature. NanoRes.2018, 11(12): 6190–6196