On the evolution and electronic properties of self-assembled gold nanowires

The crucial importance for implementing nanomaterials to nanotechnology applications is their characterization in terms of structure and properties. Here we present electronic and conductive properties of seven different gold nanowires (1. zigzag, 2. rhomboid, 3. ladder, 4. c-ribbon, 5. h-ribbon, 6. pentagonal pyramid and 7. capped pentagonal bipyramid) that can be formed due to self assembly from the linear atomic chain. From density functional calculations backed up with molecular dynamics, nudged elastic band and geometry Optimizations, it was found that, by reducing the tension on the linear atomic chain of gold atoms, it spontaneously self-assembles into one of the observed, energetically more stable motifs. It is revealed that as self assembly progresses, the electronic property of the motifs undergo semi-metallic -> semiconducting -> metallic transformatio ns. The observed electronic behavior is further supported by the current-voltage (I-V) characteristics. It is noticed that few selective structures exhibit perfect linear behavior of I-V curve whereas rest follow typical semiconductor curve. Interestingly, pentagonal pyramid displays perfect negative differential resistance with a high peak to valley ratio (PVR) of 17.25 which ensures its potential for oscillators application. Our findings include the possibility of tailoring the electronic properties of gold NW during their evolution in self assembling process. (C) 2017 Elsevier B.V. All rights reserved.