Edge and surface functionalization on prolonged and narrow zigzag- graphene nanoribbon with -COOH, -OH, -O, -NH2 group

Abstract

In this report, we have analyzed the effect of functionalization on prolong and narrow zigzag graphene nanoribbon (ZGNR). The functionalization site is selected on edges and surface of ZGNR in order to determine its stability towards functional group attachment in terms of cohesive energy calculations. The functional groups are carefully selected i.e carboxylic (-COOH-), alcoholic (-OH-), amine (-NH₂-) and epoxy (-O-). As functionalization of these groups are significant from synthesis and nanodevices application point of view of ZGNR. The geometrical stability examinations shows that functional groups are more stable at edge site in comparison to surface site. The effect of functionalization on the electronic properties and quantum charge transport characteristic are investigated in detail. The analyses of electronic properties evidence the metallic behavior of ZGNR in both the cases (edge and surface) functionalization. However, variation in energy gap (Eg) between conduction and valance results in diverse outcomes that deviates the quantum transport properties. It has been observed that edge functionalization produces significant changes in I-V characteristics of ZGNR in comparison to surface functionalized ZGNR. The multiple negative differential resistance (NDR) in I-V characteristics is observed in case of edge functionalization and non-linear I-V characteristics for surface functionalization.