A junction between metallic and semiconducting graphene nanoribbons is often proposed as a potential novel transistor structure (see e.g. Ren et al., Chinese Journal of Chemical Physics 20, 489 (2007)
). We also used this structure in the ATK tutorial on graphene
, where the structure was built by piecing together two armchair segments (electrodes) and the zigzag central region by hand. This involved quite a few complex steps, so I decided to make a simple script that constructs the complete geometry in one shot!
So, here it is - I hope it will be useful!
To use it, just load it into any editor, set the relevant parameters in the top of the script. The following aspects of the geometry can be easily controlled this way:
- Width across (number of atomic layers) of the armchair segments
- Number of armchair unit cell repetitions in both electrodes, as well as in the central region (screening surface layers)
- Number of zigzag unit cell repetitions in the central region
- C-H and C-C bond length
- XY unit cell padding
Then just drop the script on the Nanoscope in VNL to visualized the geometry, and then, if you are happy with it, on the NanoLanguage scripter to set up the calculation. An example is included as a picture.