Imaging atomic vacancies in commercially available black phosphorus

Abstract

Black phosphorus (BP) is receiving significant attention because of its direct 0.4-1.5 eV layer-dependent band gap and high mobility. Because BP devices rely on exfoliation from bulk crystals, there is a need to understand native impurities and defects in the source material. In particular, samples are typically p-doped, but the source of the doping is not well understood. Here, we use scanning tunneling microscopy and spectroscopy to compare atomic defects of BP samples from two commercial sources. Even though the sources produced crystals with an order of magnitude difference in impurity atoms, we observed a similar defect density and level of p-doping. We attribute these defects to phosphorus vacancies and provide evidence that they are the source of the p-doping. We also compare these native defects to those induced by air exposure and show they are distinct and likely more important for control of electronic structure. These results indicate that impurities in BP play a minor role compared to vacancies, which are prevalent in commercially-available materials, and call for better control of vacancy defects.

References in corpus (24)

• Black phosphorus field-effect transistors
• Phosphorene: A New 2D Material with High Carrier Mobility
• Rediscovering Black Phosphorus: A Unique Anisotropic 2D Material for Optoelectronics and Electronics
• Fast and broadband photoresponse of few-layer black phosphorus field-effect transistors
• Semiconducting Black Phosphorus: Synthesis, Transport Properties and Electronic Applications
• Effective Passivation of Exfoliated Black Phosphorus Transistors against Ambient Degradation
• The Renaissance of Black Phosphorus
• Electric field effect in ultrathin black phosphorus
• Environmental instability of few-layer black phosphorus
• Photovoltaic effect in few-layer black phosphorus PN junctions defined by local electrostatic gating
• Oxygen defects in phosphorene
• Electrical characterization of fully encapsulated ultra thin black phosphorus-based heterostructures with graphene contacts
• Quantum Hall Effect in Ultrahigh Mobility Two-dimensional Hole Gas of Black Phosphorus
• Gate-Controlled Ionization and Screening of Cobalt Adatoms on a Graphene Surface
• Defect in Phosphorene
• Toward a realistic description of multilayer black phosphorus: from $GW$ approximation to large-scale tight-binding simulations
• Highly Itinerant Atomic Vacancies in Phosphorene
• Native point defects in few-layer phosphorene
• Probing Single Vacancies in Black Phosphorus at the Atomic Level
• The Role of H2O and O2 Molecules and Phosphorus Vacancies in the Structure Instability of Phosphorene
• STM images of sub-surface Mn atoms in GaAs: evidence of hybridization of surface and impurity states
• Charge carrier transport and lifetimes in n-type and p-type phosphorene as 2D device active materials: an ab initio study
• Surface buckling of phosphorene materials: determination, origin and influence on electronic structure
• Influence of surface-related strain and electric field on acceptor wave functions in Zincblende semiconductors

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• STM Study of Exfoliated Few Layer Black Phosphorus Annealed in Ultrahigh Vacuum
• Long-Term Environmental Stability of Nitrogen-Healed Black Phosphorus
• Electronic Self-passivation of Single Vacancy in Black Phosphorus via a Controlled Ionization
• Evolution of Intrinsic Vacancies and Prolonged Lifetime of Vacancy Clusters in Black Phosphorene
• Thermoelectric response across the semiconductor-semimetal transition in black phosphorus
• Black Phosphorus n-type doping by Cu: a microscopic surface investigation
• Band gap reconstruction at the interface between black phosphorus and a gold electrode
• Substitutional tin acceptor states in black phosphorus
• Mechanistic insights on the phosphorene degradation