Optical Engineering of Biphenylene and Graphene Nanoribbons

Confinement of electrons and strong light-matter interactions in graphene-based nanoribbons give rise to behavior not obtainable in bulk material. Such nanoribbons show potential to be used for numerous optoelectronic applications including field effect transistors, optical absorbers, and low noise biosensors. The optoelectronic properties of graphene nanoribbons are readily manipulated through multiple approaches: cutting direction, width, strain, electronic doping, and edge functionalization. Fan et. al. have recently reported on a procedure to synthesize quasi-1D nanoribbons based on biphenylene networks, another sp² hybridized carbon allotrope. Choice of carbon allotrope provides another method for engineering the optoelectronic properties of nanoribbons. We report on the results of high throughput DFT calculations for a wide array of biphenylene and graphene based nanoribbons. Nanoribbon structures are evaluated for phase, bandgap, dielectric function, and absorption. Machine learning is used to identify trends between nanoribbon structure and optical properties and predict new structures with desired optical response.