Estudo de dopagem no Fosforeto de Carbono bidimensional (2D) e interações com moléculas

Abstract

The wide variety of impressive physical and chemical properties of two­dimensional (2D) materials, along with the possibility of modifying the electronic properties of these materials, such as applying pressure, external field or doping, opens up a huge range of possible applications. In this sense, finding nanodevices capable of detecting and distinguishing gas molecules through electrical identification is a major challenge for researchers. This work explores the electronic and transport properties of CarbonPhosphide (CP), doped and pristine, through a combination of Density Functional Theory ( DFT) and Non­Equilibrium Green’s Functions (NEGF). Initially we studied the substitutional doping on γ­CP (semimetallic) for the following situations: (i) substitution of atoms of carbon by boron and nitrogen atoms, and (ii) substitution of atoms of phosphorus by silicon and sulfur atoms. The formation of the B­doped γ­CP (γ­CP­B) is ruled by an exothermic process and the doping leads to an increase in the number of bands crossing the Fermi level, contributing to increment the number of transmission channels, when compared to the pristine one. Furthermore, we conducted, a systematically investigation of the interaction between CO, CO2, NO and NH3 molecules and the surface γ­CP­B. The results showed that there is a modulation on the transmission for each target molecule adsorbed on the surface of B­doped γ­CP, being possible to distinguish between each one by material’s conductance. These results poses the γCP­B as a promising candidate to be used as a gas sensor, with high sensitivity and ability to select among the group of target molecules.