Electronic properties of two-dimensional nanocarbons formed by truxene-like building blocks

Abstract

Nanocarbons obtained from well-known molecular precursors can provide nanostructures with a diversity of electronic behaviors. In addition to an array of theoretical results, experimental studies have motivated developments in the field with the growth of quantum dots with nontrivial configurations of nonhexagonal rings. For example, a truxene (Trx) molecular unit can display either a $s{p}^3$-carbon-containing configuration or a full-$s{p}^2$ variation. The $s{p}^3$ case has a large gap between its frontier states, unlike the $s{p}^2$ counterpart, which has unpaired electrons. Here, we use computational simulations to propose a set of Trx-based 2D nanocarbons with electronic properties dictated by the anchoring points of the block-to-block connections. The interplay between Trx’s molecular levels and details of the 2D lattices results in systems ranging from metals to wide-gap semiconductors. This versatility is rationalized in terms of $\pi$ bonds formed through unpaired electrons from sequential Trxs, as verified with the aid of a graph-theoretical analysis.