Potential of AMnO3 (A=Ca, Sr, Ba, La) as Active Layer in Inorganic Perovskite Solar Cells.

Inorganic perovskite CaMnO 3 ${{}_{3}}$ was proposed as a substitution for the TiO 2 ${{}_{2}}$ anatase in electron transport layers of solar cells containing the hybrid perovskite CH 3 ${{}_{3}}$ NH 3 ${{}_{3}}$ PbI 3 ${{}_{3}}$ based on increased mobility of electrons and better optical matching. Due to a suitable band gap concerning the absorption of sunlight, we investigate the potential of CaMnO 3 ${{}_{3}}$ and similar manganite perovskites, where Ca is replaced by either Sr, Ba or La, as an absorber layer in inorganic perovskite solar cells. In this study, we have used optical measurements on the synthesized AMnO 3 ${{}_{3}}$ (A=Ca, Sr, Ba, La) samples to aid density functional theory calculations (DFT) in order to accurately simulate the electronic and optical properties of AMnO 3 ${{}_{3}}$ compounds and gauge their potential for the role of absorber layer. Both experimental measurements and theoretical calculations show suitable band gap of 1.1-1.5 eV, depending on the compound, and absorption coefficients of the order of 10 5 ${{10}^{5}}$ cm - 1 ${{}^{-1}}$ in the visible part of the spectrum.

Effect of electric field on optoelectronic properties of indiene monolayer for photoelectric nanodevices.

In recent years, layered materials display interesting properties and the quest for new sorts of two-dimensional (2D) structures is a significance for future device manufacture. In this paper, we study electronic and optical properties of 2D indiene allotropes with planar and buckled structures. The optical properties calculations are based on density functional theory (DFT) simulations including in-plane and out-of-plane directions of light polarization. We indicate that the optical properties such as complex refractive index, absorption spectrum, electron energy loss function (EELS), reflectivity and optical conductivity spectra are strongly dependent on the direction of light's polarization. High values and narrow peaks in optical spectra introduce indiene to the field of ultra-thin optical systems. The effect of external static electric field on electronic and optical properties of indiene is also observed and discussed. We show that the band gap in buckled indiene can be effectively changed by applying the external electric field. The discoveries here expand the group of 2D materials beyond graphene and transition metal dichalcogenides (TMDs) and give valuable data for future experimental realization of new mono-elemental materials with conceivable applications in optical devices.

Spin-dependent electron transport in C and Ge doped BN monolayers.

Recent advances in the synthesis and characterization of h-BN monolayers offer opportunities to tailor their electronic properties via aliovalent substitutions in the lattice. In this paper, we consider a h-BN monolayer doped with C or Ge, and find that dopants modify the Fermi level of the pristine monolayer. Three-fold coordinated dopants relax to the convex-shaped structures, while four-fold coordinated ones retain the planar structures. These modifications, in turn, lead to unique features in the electron transport characteristics including significant enhancement of current at the dopant site, diode-like asymmetric current-voltage response, and spin-dependent current. We find that the spin-polarized transport properties of the doped BN monolayers could be used for the next-generation devices at the nanoscale.

Modeling of diameter-dependent Fe and Co ultrathin nanowires from first-principles calculations.

We present the electronic, magnetic, thermoelectric and optical properties of ferromagnetic metal nanowires (NWs) made of iron (Fe) and cobalt (Co) atoms using a first principles approach. Each property has been investigated as a function of atomic arrangement and nanowire diameter. Magnetic anisotropy is predicted originating from the spin-orbit coupling. Significant delocalization of electronic charge density is found in Fe nanowires with the increase in nanowire diameter, while the charge distribution anisotropy manifests in all the studied nanowire configurations. The thermoelectric properties exhibit strong coupling to the nanowire configuration and diameter. Thermal conductivity shows large divergence from the bulk iron and cobalt. The optical properties show the strongest increase for nanowires with large diameters. The theoretical modeling of configuration- and diameter-dependent nanowire properties serves as a cornerstone for future utilization of nanowire films in a variety of applications.

First step to investigate nature of electronic states and transport in flower-like MoS2: Combining experimental studies with computational calculations.

In the present paper, the nature of electronic states and transport properties of nanostructured flower-like molybdenum disulphide grown by hydrothermal route has been studied. The band structure, electronic nature of charge, thermodynamics and the limit of phonon scattering through density functional theory (DFT) has also been studied. The band tail states, dynamics of trap states and transport of carriers was investigated through intensive impedance spectroscopy analysis. The direct fingerprint of density and band tail state is analyzed from the capacitance plot as capacitance reflects the capability of a semiconductor to accept or release the charge carriers with a corresponding change in its Fermi potential levels. A recently introduced infrared photo-carrier radiometry and density functional perturbation theory (DFPT) techniques have been used to determine the temperature dependence of carrier mobility in flower type-MoS2. The present study illustrates that a large amount of trapped charges leads to an underestimation of the measured effective mobility and the potential of the material. Thus, a continuous engineering effort is required to improve the quality of fabricated nanostructures for its potential applications.

Efficiency of colored modified box traps for sampling of tabanids.

The efficiency of ten differently colored modified box traps for collecting tabanids was studied in the Monjoros Forest in eastern Croatia. A total of 5,436 specimens belonging to 16 species of tabanids grouped into six genera were collected. The genus Tabanus was the most represented with 98% of all collected tabanids. Tabanus bromius comprised 90% of tabanids collected, and was the most abundant species collected in all box traps. The majority of tabanids (74%) were collected from black, brown, bordeaux, red, and blue traps (dark group), whereas 26% were collected from green, light violet, white, orange, and yellow traps (light group). The black modified trap was the most successful and collected 20% of all collected tabanids, whereas the yellow trap was the least effective with 1%. The number of collected specimens of species T. bromius differed significantly between the dark and light group of traps. Traps with lower reflectance from green color collected 77% of T. bromius. The most species of tabanids (12) was collected in the brown trap, whereas the least number of species (6) was collected in the yellow trap.