1. Intoduction

Graphene is an alternative material to use in low dimensional structures. Recently study of graphene based devices is growing rapidly [1]-[3]. Graphene is single layer of carbon atoms that arranges in honeycomb structure [4]. Graphene nanoribbons (GNRs) have attracted much attention because of their properties and their potential in designing high performance devices [5]-[6]. Graphene nanoribbon is finite- width Graphene strips and has quasi 1D structure. However recently isolated nanometer sized GNRs have been actually synthesized by etching large graphene samples or by CDV growth on suitable patterned surfaces. Optimizing fabrication methods opens vast application areas for GNRs [7]-[9].