Use of the Adsorbed Organic Molecules as Dopants for Creation of the Built-in Lateral p-n Junctions in a Sheet of Black Phosphorene.

This article discusses the attempt to create the built-in lateral p-n junctions in a sheet of black phosphorene using the adsorbed organic molecules as dopants. Within the framework of the methods of the electron density functional and the ab initio pseudopotential, the valence electron density spatial distributions, the densities of electronic states, the band gaps and the core charges of a sheet of black phosphorene were obtained. On the sheet of black phosphorene, there was a homogeneous distribution of the valence electron density. The adsorption of carbamide molecules for diverse types of localization on the surface of a black phosphorene sheet led to the redistribution of electron density in it. It was evident that the charge regions of greater density in a black phosphorene sheet with adsorbed carbamide molecules were localized under the atoms of carbamide molecules, forming a common region of the electronic density elevated concentration. The removal of the molecules led to a decrease in their effect on the redistribution of the valence electron density in a black phosphorene sheet. The accumulation of the electric charge of a black phosphorene sheet in the region under the carbamide molecules in turn led to the emergence of regions on the black phosphorene sheet, in which the core charges changed the sign to the opposite. The homogeneity of the distribution of electron density in the black phosphorene sheet disappeared and areas of a spatial charge of different signs were formed. Such areas with charges of different sings create conditions, which are the main characteristic of p-n junctions. Also it was established that the adsorption of the black phosphorene sheet with carbamide molecules led to a change in conductivity of a black phosphorene sheet. [ABSTRACT FROM AUTHOR]