Perovskite-based solar cells are becoming a subject of interest in photovoltaic research area, owing to their high efficiency, abundance, and low cost. In this work, we report the means to calculate the crucial parameters requested by the industrial community such as Short Circuit Current, Open Circuit Voltage, Quantum Efficiency, and electrical power of a given photovoltaic material from ab-initio calculations. This method opens the ability to master the correlation between synthesis and efficiency of all photovoltaic materials without realizing the photovoltaic device. As example of material, CH3NH3PbI3 perovskite is chosen. Firstly, the density of state and optical dielectric constant were calculated using FLAPW method based on density functional theory principle. From both physical quantities, quantum efficiency, Voc, Jsc, and electrical power were estimated. All computed curves and values were compared to experimental data and discussed in terms of photovoltaic efficiency improvement.

Single crystal of 1D homometallic coordination polymer involving cobalt metal ion and P2Mo5 Strandberg type polyoxometallate cluster (C6H10N2)2[Co(H2O)4P2Mo5O23].6H2O, is prepared in aqueous solution and characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance, fluorescence and magnetism. Single crystal X-ray diffraction analysis reveals that this compound crystallizes in the triclinic system with space group P $$\,\bar{1}$$1¯. The 3-(ammoniomethyl)pyridine C6H8N2 organic fragment is used merely as stabilizer for the promotion of topological structure. DRS data indicate that the synthesized material can be identified as a ferromagnetic semiconductor with optical bands gaps energy of 1.81 and 2.74 eV, respectively. The large value of refractive index observed in the visible region make the simple a promising candidate for visible optical communication devices and fluorescent emisson result provides that the complex belongs to a blue luminescent compounds. Moreover, magnetic measurements and electronic structure calculations show that P2Mo5 Strandberg polyoxoanion can be reported as a new class of ligand that is candidate to construct metal-inorganic framworks with long distance ferromagnetic superechange between Co(II) centers. The evidence from this study suggests that the syntesized polymer can become a great multifunctional material openning the door for the developpement of new coordination polymers based on Strandberg type polyxoxmetalate with potential applications.

No abstract

No abstract

The electronic, optical, magnetic, and thermoelectrical properties of both, the monoclinic (α-form) and the orthorhombic (β-form) phases of sodium manganese (II) arsenate NaMnAsO 4 cluster are investigated comprehensively by the first-principle calculations based on the Density Functional Theory. The fullpotential linearized augmented plane waves method within the generalized gradient approximation (GGA) and GGA + U approaches have been performed by the Wien2k software. Thermodynamic stability is confirmed by means of formation energy (ΔH f ). The spin-polarization is included in the calculations to study the electronic and magnetic properties. The indirect bandgaps are observed for the monoclinic phase, then the direct bandgaps are reported at Γ-symmetry point for the orthorhombic phase. The density of state, besides the band structure calculation, revealed that the studied material can be identified as a ferromagnetic semiconductor at low temperature with an optical bandgap energy of 1.35 and 0.83 eV for monoclinic and orthorhombic phases with GGA approach, as well as 1.27 and 1.59 eV with GGA + U approach, respectively. The refractive index range is 1.5 to 2.4 along with a wide absorption band in the UV region, which makes this material outstanding for optoelectronic devices. The thermoelectric properties for both structures have also been investigated using the BoltzTraP package. The obtained electrical conductivity, as well as the figure of merit, are found to be important for thermoelectrical devices. This suggests that NaMnAsO 4 could pave the way to further experimental research on optoelectronicthermoelectric applications.