Chemical modifications and stability of phosphorene with impurities: a first principles study

Abstract

We perform a systematic first-principles study of phosphorene in the presence of typical monovalent (hydrogen and fluorine) and divalent (oxygen) impurities. The results of our modeling suggest a decomposition of phosphorene into weakly bonded one-dimensional (1D) chains upon single- and double-side hydrogenation and fluorination. In spite of a sizable quasiparticle band gap (2.29 eV), fully hydrogenated phosphorene was found to be dynamically unstable. In contrast, complete fluorination of phosphorene gives rise to a stable structure, which is an indirect gap semiconductor with a band gap of 2.27 eV. We also show that fluorination of phosphorene from the gas phase is significantly more likely than hydrogenation due to the relatively low energy barrier for the dissociative adsorption of F2 (0.19 eV) compared to H2 (2.54 eV). At low concentrations, monovalent impurities tend to form regular atomic rows of phosphorene, though such patterns do not seem to be easily achievable due to high migration barriers (1.09 and 2.81 eV for H2 and F2, respectively). Oxidation of phosphorene is shown to be a qualitatively different process. Particularly, we observe instability of phosphorene upon oxidation, leading to the formation of disordered amorphous-like structures at high concentrations of impurities.

The atomic and electronic structure of nitrogen- and boron-doped phosphorene

“…These changes in the atomic structure cause changes in the overlaps between phosphorous and nitrogen orbitals and especially between sigma orbitals with lone pairs of electrons (see discussion in Ref. [11]), which leads to light doping of the phosphorene matrix from nitrogen (Table I). …”

“…[6] One issue in the further application of phosphorene is its chemical stability under ambient conditions, which has been recently discussed both experimentally [7][8][9] and theoretically. [10,11] Recent experimental [12] and theoretical [13,14] works discuss valuable changes in the electronic structure and chemical properties of boron-and nitrogen-doped graphene. Nitrogendoped graphene has been discussed as a possible catalyst for the oxygen reduction reaction.…”

Chemical instability of free-standing boron monolayers and properties of oxidized borophene sheets

“…[17] Based on results of the modelling that demonstrate similarity for two representative samples of different types of BSs can propose that our results are valid for all BSs. Therefore, similarly to the phosphorene, [56,57] BSs require fabrication of additional protective cover made from chemically inert material (for example hBN). [65] From the other hand, oxidized BSs (OBSs) can be interesting by itself and further we provide evaluation of the properties of these materials that can be used in further applications.…”

Nitrogen dioxide and ammonia gas molecules interaction studies on phosphorene nanosheet — a DFT investigation

“…The HOMO-LUMO gap of H-PNS and F-PNS are found to be 2.64 and 2.58 eV, respectively. Boukhvalov et al [43] reported the stability and chemical modification of phosphorene with the influence of fluorine and hydrogen. They calculated the energy gap value for two different structural configurations of fully hydrogenated PNS, which is noticed to be 2.29 eV and 2.64 eV, respectively.…”