Mechanistic insights in phosphorene degradation

Abstract

The structural and chemical degradations of phosphorene severely limit its practical applications despite the enormous promise. In this regard, we investigate a plethora of microscopic kinetic mechanisms and develop a degradation phase diagram within the first-principles calculations. At 400 K, the degradation and the competing self-annealing proceeds through the merger and annihilation of vacancies, respectively, which are triggered via itinerant vacancy and adatom. A further increase in temperature beyond 650 K, the structural degradation results through the emission of the undercoordinated atoms from the defect and the concurrent pair-wise sublimation. The role of inter-layer vacancy diffusion is discarded in the context of structural degradation. The chemical degradation is routed through the dissociation of oxygen molecule that is either activated at the room-temperature on the pristine surface or spontaneous at the single-vacancy site. The present results are in agreement with the few available experimental conjectures and will motivate further efforts.arXiv:1904.08822v1 [cond-mat.mes-hall]

Electronic Self-passivation of Single Vacancy in Black Phosphorus via a Controlled Ionization

“…1a, removal one P atom from the buckled lattice in BP creates an SV and leaves DBs at three adjacent P sites . Neutral SVs in BP are predicted to possess in-gap electronic states, which play an essential role in modulating electronic and optical properties of BP and thus affecting their device characteristics [11,[25][26][27][28][29]. Despite advances in BP research, the atomic-scale structural and electronic properties of SVs and their impact on charge dynamics in BP remain elusive.…”