Electronic and optoelectronic properties of black phosphorous

Herein, we present the enormous capabilities of the most recent rediscovered 2D material named black phosphorous (BP). It offers a solution for several technological limitations that appears in conventional 2D materials such as transition metal dichalcogenides/oxides etc. In the present work, we have demonstrated the electronic and optoelectronic properties of BP via realizing field effect transistors.

Bandgap Engineering Of Black Phosphorus-Based Nano Structures

In this work, first-principles calculations based on Density Functional Theory (DFT) were employed in order to investigate the electronic properties of Black Phosphorus and its 2D and 1D derivatives, named Phosphorene and Phosphorene Nanoribbons (PNRs) respectively. The electronic structures of the black phosphorus-based nanostructures were firstly examined. Our results demonstrate that all dimensions behave as semiconductors except for the zigzag nanoribbons which are shown to be metals. Furthermore, we extended our study to include different strategies to engineer the bandgap of the two-dimensional phosphorene and the one-dimensional phosphorene nanoribbons either by stacking a multiple number of the phosphorene layers, exercising a tensile or compressive strain or by edge-passivating the phosphorene nanoribbons with Hydrogen. Our study reveals that the bandgaps and the electronic properties of these black phosphorus-based nanostructures are very flexible and several approaches could be adopted in order to engineer them

An easy route to synthesis black phosphorus at low pressure and soft conditions

Black phosphorus a promising candidate for large application, due to his variety of structural and physical properties, can be prepared by a very low-coast reaction route with high purity and crystallinity. Black phosphorus is prepared from red phosphorus at 873K under reduced pressure using a simple and low cost catalytic system. The quality of crystal with lattice parameters a=3.31Å, b=10.48Å, c=4.37Å can be approved by a series of characterizations like scanning microscopy electron (SEM), energy dispersive spectrometry (EDX), Raman spectroscopy and powder X-rays. The new preparation method of black phosphorus represents an easy, effective and low cost approach to avoid complicated preparative setups, toxic catalysts, or “dirty” flux methods and is of general interest in elemental chemistry

Structural and Magnetic Properties of Nanosized strontium Hexaferrite Powders: Experimental and theoretical investigation

Strontium M-type hexagonal ferrites were synthesized at different calcination temperatures (800 °C, 1000°C and 1100 °C) using sol-gel autocombustion method. Thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Mössbauer spectroscopy (MS) and superconducting quantum interference device magnetometer (SQUID) techniques were used to characterize crystal structure, phase composition, morphology and magnetic properties. TGA gives T=800 °C as beginning of suitable calcination. Hexaferrite structure of single phase is obtained according to XRD results for all samples with crystallite size between 28 nm and 35 nm. SEM images show the growth of grain size with increasing of annealing temperature. (BH)max is calculated based on SQUID results and shows an enhancement between T=800°C and T= 1000°C of 25%. The magnetic properties observed at low temperature are explained and confirmed by ab-initio calculations

Energy product and magnetic properties of strontium hexagonal ferrite: experimental and theoretical investigation

The interest toward hard magnetic materials increases in the last years. In order to have the best magnetic properties of these materials, researchers count on the efficiency of different synthesis methods. In permanent magnets application, ferrite materials possess a good place among the other magnet families. In permanent magnets field, the more important parameter that describes the magnetic strength of a magnet is the maximum energy product (BH)max. A strong permanent magnet has an important value of (BH)max. In this work, we will study the effect of annealing temperature on maximum energy product and other magnetic properties of Strontium hexaferrite SrFe12O19 synthesized using sol-gel autocombustion method, with different annealing temperatures, characterized using Thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Mössbauer spectroscopy (MS) and superconducting quantum interference device magnetometer (SQUID). Ab initio calculation for magnetic properties is also performed in order to compare it with low temperature experimental results

Arsenic 2D a New Anode Material for Rechargeable Batteries: First Principal Calculation

International audienc

Influence of iron substitution on the ferromagnetic ordering and magnetic entropy variation in La1-Na Mn1-Fe O3 (x = 0.1, 0.2 and y = 0, 0.1)

International audienc

Improved Power Conversion Efficiency with Tunable Electronic Structures of the Cation-Engineered [A_i]PbI₃ Perovskites for Solar Cells: First-Principles Calculations

Higher power conversion efficiencies for photovoltaic devices can be achieved through simple and low production cost processing of APbI3(A=CH3NH3,CHN2H4,…) perovskites. Due to their limited long-term stability, however, there is an urgent need to find alternative structural combinations for this family of materials. In this study, we propose to investigate the prospects of cation-substitution within the A-site of the APbI3 perovskite by selecting nine substituting organic and inorganic cations to enhance the stability of the material. The tolerance and the octahedral factors are calculated and reported as two of the most critical geometrical features, in order to assess which perovskite compounds can be experimentally designed. Our results showed an improvement in the thermal stability of the organic cation substitutions in contrast to the inorganic cations, with an increase in the power conversion efficiency of the Hydroxyl-ammonium (NH3OH) substitute to η = 25.84%

Coupling between magnetic and optical properties of GaN:TM (TM: V, Cr, Mn, Fe, Co, Ni): First-principle study with LDA-SIC approximation

International audienc