Pristine Blue Phosphorene Research Articles

Modeling the aluminum-doped and single vacancy blue phosphorene interactions with molecules: a density functional theory study.

Structural, electronic, binding energies and magnetic properties of aluminum-doped and single vacancy blue phosphorene interacting with pollutant molecules are investigated using the density functional theory (DFT) with periodic boundary conditions. Acetylene, ozone, sulfur trioxide, hydrogen selenide, and sulfur dichloride molecules are considered to show the efficiency and enhancement of the sensing properties in comparison with the pristine blue phosphorene. Acetylene, sulfur trioxide, hydrogen selenide, and sulfur dichloride show chemisorption (> 0.5eV/molecule) when interacting with the aluminum-doped system, but the ozone molecule dissociates in all configurations and symmetry sites. On the other hand, the acetylene, ozone, and sulfur trioxide with the single vacancy blue phosphorene exhibit chemisorption, the hydrogen selenide molecule exhibit a weak interaction energy, and the sulfur dichloride dissociates in all configurations and symmetry sites. In all the cases, the enhancement in the interaction energy was achieved when compared to other results for the same molecules. Finally, the single vacancy blue phosphorene shows a magnetic moment of ~1 μB/supercell, as induced by the vacancy.

First-principles study of pristine and metal decorated blue phosphorene for sensing toxic H2S, SO2 and NO2 molecules

First-principles calculations based on density functional theory (DFT-D2 method) are employed to systematically investigate the adsorption behaviors of toxic gas molecules (H2S, SO2 and NO2) on pristine and metal (Li, Al, Ni and Pt) decorated blue phosphorene. The results for small adsorption energy, charge transfer and large adsorption distance reveal that the adsorption of H2S, SO2 and NO2 on pristine blue phosphorene is physisorption. It has been proved that the adsorption ability of pristine blue phosphorene to gas molecules can be improved by metal decorating, except for H2S adsorbed on Al decorated blue phosphorene. Our calculations show that the gas molecules absorbed on metal decorated blue phosphorene belong to chemisorption with relatively large adsorption energies and charge transfer, while the H2S adsorbed on Li and Al decorated blue phosphorene are still physisorption. Meanwhile, the significant conductivity changes of these systems mean the sensitivity of gas molecules improved. From the calculated recovery time, we find that gas molecules desorption from metal decorated blue phosphorene is possible. Therefore, these results indicate that metal decorated blue phosphorene could be ideal candidate for better adsorption or detection toxic H2S, SO2 and NO2 molecules.

Adsorption of single alkali-metal atoms (Li, Na, K) over the edge-passivated zigzag blue phosphorene nanoribbons

In the wake of blue phosphorene’s theoretical prediction and experimental synthesis, it has emerged as an excellent candidate for anode materials in alkali-metal-ion batteries due to its outstanding electrochemical performance. In the work, we have addressed the impact of edge passivation by both hydrogen (H) and oxygen (O) atoms on single adsorption of different alkali-metal atoms (Li, Na, K) over zigzag blue phosphorene nanoribbons (ZBPNRs) using first-principles calculations. Our results unravel that in the presence of edge H-passivation, the nanoribbon binds alkali-metal atoms inferior to the pristine blue phosphorene with binding energies varying from −1.53 to −1.90eV. A complete suppression of binding even occurs at the passivated edge. By contrast, the binding of adatoms is substantially enhanced by passivating the edge of the nanoribbon with O atom. The enhancement in binding not only appears at the edge but also extends across the entire nanoribbon under study. More importantly, the edge of O-passivation binds alkali-metal atoms most strongly amongst all sites, with adsorption energies between −3.93 and −4.83eV. These observations show that the edge O-passivation is highly important to make the adsorption of alkali-metal atoms over ZBPNRs more stable thermodynamically, which can be used to further tailor the nanoribbon’s electronic and magnetic properties. Overall, strengthening of the binding of these alkali-metal atoms to the ZBPNRs of edge O-passivation has clear technological implications for the design and development of electrochemical energy storage devices.

First-principles study of CO and NO adsorption on pristine and transition metal doped blue phosphorene

First-principles calculations within the density functional theory (DFT-D2 method) is carried out to systematically investigate the structural, energetic, electronic and magnetic properties of toxic CO and NO gas molecules on pristine and transition metal (TM) atom (Fe, Co, Ni, Pd, Ag and Pt) doped blue phosphorene. Our calculations show that the CO and NO molecules are physisorbed on pristine blue phosphorene due to small adsorption energies, charge transfer, and large adsorption distances of the adsorbed systems. TM doping can significantly enhance the interaction between the gas molecules and the blue phosphorene, leading to the CO and NO molecules absorbed on TM doped blue phosphorene belong to chemisorption with relatively large adsorption energies and charge transfer, except for CO adsorbed on Ag doped blue phosphorene. Meanwhile, the enhancing interaction between the gas molecules and TM doped blue phosphorene can dramatically induce magnetism and electrical conductivity changes. These results indicate that TM doped blue phosphorene is a potential candidate to develop novel two-dimensional phosphorene-based gas sensors.

The investigation of optoelectronic, magnetic and dynamical properties of Ce and Ti doped 2D blue phosphorene: A dispersion corrected DFT study

The present study has been performed to investigate optoelectronic, magnetic and dynamical properties of pristine blue phosphorene (BP), (Ce, Ce–Ce, Ti, Ti–Ti) doped BP and single vacancy BP using the Cambridge Serial Total Energy Package (CASTEP) simulation code based on the density functional theory (DFT). The optical and vibrational properties were carried out by employing dispersion corrected density functional theory. The calculated lattice constants for pristine blue phosphorene a = b = 3.33 Å are found to be improved by Tkatchenko-Scheffler (TS) and Grimme (G06) schemes for 2D phosphorene. The band structures and density of states results have figured out indirect band gaps as 1.93eV (pristine), 0.35eV (with single vacancy), 0.37eV (Ce doped), 0.68eV (Ti doped), and 0.56eV (Ti–Ti doped) in blue phosphorene. Whereas, no band gap has been observed for Ce–Ce doped blue phosphorene. The phonon dispersion curves obtained by density functional theory perturbation theory presented dynamical stability of the studied materials without any imaginary modes of phonon spectra. The Raman active optical modes of vibrations are found at the highest frequency of 520 cm−1. The Spin polarized density of states portray that (Ce, Ti, Ti–Ti) doped blue phosphorene exhibit semi-metallic like behavior due to hybridization of 4f, 5d and 3d localized energy states. The optical properties show that the plasma frequencies occurred at 11.34eV (pristine), 8.6 eV (Ce-doped) and 9.03eV (Ti-doped) blue phosphorene. Moreover, significant shift of absorption peak towards high energy range is clear signature of the blue shift.

Interactions of selected organic molecules with a blue phosphorene monolayer: self-assembly, solvent effect, enhanced binding and fixation through coadsorbed gold clusters.

In this paper we investigate the interaction between a pristine blue phosphorene monolayer and selected organic molecules like amino acids and nucleic acid bases. These molecules are bound to the substrate by a weak van der Waals interaction leading to their physisorption. When isolated, they tend to orient themselves parallel to the surface and are located in flat minima with very low libration frequencies; thus the electronic structures of the substrate and physisorbed molecules are not affected except for relative shifts. Even though the regular self-assembly of these molecules on the pristine blue phosphorene cannot be realized under this weak interaction, only their irregular coating of the substrate can occur due to increased intermolecular coupling. In a solvent like water, the weak binding energy is further decreased. Gold adatoms and gold clusters can form strong chemical bonds with pristine blue phosphorene and modify its electronic and magnetic state depending on the coverage. While full coverage of a blue phosphorene monolayer by gold adatoms leads to instabilities followed by clustering, relatively lower coverage can attribute very interesting magnetic and electronic states, like a spin gapless semiconductor. When bound to the gold clusters already adsorbed on the blue phosphorene monolayer, amino acid and nucleic acid base molecules form relatively strong chemical bonds and hence can be fixed to the surface; they are reoriented to gain self-assembly character and the whole system acquires new functionalities.

Vibrational properties and Raman spectra of pristine and fluorinated blue phosphorene.

Using density functional theory, we investigated the vibrational properties and Raman spectra of pristine blue phosphorene and fluorinated blue phosphorene. The fluorinated blue phosphorene possesses a Dirac cone at the K point (about 310 cm-1). The shape of the Dirac cone remains unchanged under different tensile strains. The Raman tensor and thus angle-dependent Raman intensities of all Raman active modes are calculated for the polarizations of scattered light parallel and perpendicular to that of the incident light. The characteristics of angle-dependent Raman intensities are discussed. Moreover, the polarization direction averaged non-resonant Raman spectra of pristine blue phosphorene and fluorinated blue phosphorene are compared with that of germanene and black phosphorene.

Hydrogen adsorption on alkali metal decorated blue phosphorene nanosheets

Hydrogen storage capabilities of blue phosphorene nanosheet, decorated with lithium and sodium atoms were systematically studied using ab-initio Density Functional (DFT) calculations. Hydrogen molecule adsorbs on pristine blue phosphorene with an adsorption energy of 0.06 eV, which is much lower than the threshold energy of ∼0.10 eV required for practical applications. When blue phosphorene is decorated with lithium or sodium atoms on its surface, hydrogen adsorption energies are drastically increased to 0.25 eV and 0.18 eV respectively. It is found that a lithium atom adsorbs up to three and sodium atom up to four hydrogen molecules. Analysis of density of states and difference charge density calculations confirm the hybridization of hydrogen and lithium states. Coverage studies show a gravimetric storage capacity for hydrogen to be 5.5% on lithium decorated blue phosphorene, which is better than that of lithium decorated black phosphorene (4.4%).

Theoretical design of blue phosphorene/arsenene lateral heterostructures with superior electronic properties

In-plane integration of various two-dimensional materials has recently emerged as an exciting approach to the tailoring of desired properties for novel nanoelectronic devices. Type-II lateral heterostructure (LHS) semiconductors with direct bandgap are urgently desired in photovoltaic, photocatalytic and optoelectronic devices. In this work, we design novel AsmPn LHSs with excellent stability composed of blue phosphorene and arsenene along the zigzag interline. In contrast to the wide indirect band gaps of pristine blue phosphorene and arsenene, all LHSs considered here except As2P2 possess narrower, direct gaps. As2P2 is an indirect-gap semiconductor with quasi-type-II band alignment, while the other LHSs are direct-gap semiconductors and have type-II alignment with the electrons (holes) located in monolayer blue phosphorene (arsenene). In addition, it is found these LHSs have high carrier mobilities of up to cm2 V−1 s−1. Interestingly, several attractive characteristics of BP/arsenene LHSs, including direct bandgap and high mobility, can be well preserved even if the component ratios and tensile strains are changed. As4P4 undergoes a transition from type-II to type-I-like band alignment at when we apply tensile strain along the x direction, while a transition from type-II to type-I alignment is observed at if the tensile strain is applied along the y direction. Furthermore, we have found that the energy gaps of LHSs can be effectively manipulated via the strain, width and component ratio. Our predictions highlight the potential applications of blue phosphorene/arsenene LHSs in electronics, photovoltaics, optoelectronics and photocatalysis.

Tuning electronic, magnetic, and transport properties of blue phosphorene by substitutional doping: a first-principles study

Using first-principles density functional theory, we investigated the geometrical structure and magnetic, electronic, and transport properties of blue phosphorene doped with a multitude of substitutional impurities, including both metallic and semiconducting elements. Substitutional dopants modified the properties of blue phosphorene. B, Al, Ga, Sb, Bi, and Sc substitutional dopants led to an indirect- to direct-gap transition. Blue phosphorene with C, Si, Ge, Sn, O, S, Se, and Fe substitutional dopant atoms showed dilute magnetic semiconducting properties. Furthermore, the effective mass as well as zero-bias transmission spectrum of this material support the fact that the transport properties of blue phosphorene are modified by the above-mentioned impurity atoms. The effective mass of holes for the Bi- and Sb-doped systems was about $$0.138m_{0}$$ , implying that these systems have high hole mobility. Meanwhile, the Sb-doped system exhibited the smallest effective mass for electrons of $$0.244m_{0}$$ . The results of this study illustrate that doped blue phosphorene exhibits different electronic, magnetic, transport, and optical properties from pristine blue phosphorene, which may enable many useful applications in nanoelectronics, gas sensing, optoelectronics, and spintronics.

Enhanced hydrophilic and conductive properties of blue phosphorene doped with Si atom

In this paper, the electronic, magnetic properties and the effect of Si-doped blue phosphorene on the adsorption of a H2O molecule have been investigated using density functional theory with van der Waals corrections. The results indicate that doping Si into blue phosphorene can facilitate the dissociative adsorption of H2O molecules. The dissociative energy barrier is reduced from 2.45eV on pristine blue phosphorene to 0.19eV on Si-doped blue phosphorene, which indicates a smooth dissociative adsorption. In addition, the dissociative adsorption of H2O molecules can convert the Si-doped blue phosphorene from hydrophobic to hydrophilic with a semiconductor-to-metal transition.