Theory reveals how 2D aluminum could be synthesized.

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.

Optical properties of 2D materials can be effectively modulated by employing multilayer structures with different number of layers. Using the theoretical approach based on density functional theory we simulated relevant optical spectra of antimony and indium mono-and multilayers. We showed that the electronic band structures of antimonene and indiene possess numerous tracking bands enhancing the transition probability. Therefore, high absorption coefficients are found. Modelled multilayer nanostructures of antimonene and indiene experience a red-shift of absorption bands. Antimonene exhibits an optical directional anisotropy regarding the absorbance coefficient and reflectance spectrum for different nanolayer thicknesses. Indiene possesses very high reflectance and refractive index in the visible and IR spectrum which can be effectively modulated by the number of layers. Our work shows that antimonene and indiene multilayers harbour untapped potential for the optical applications at the nanoscale.

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 105 ${{10}^{5}}$ cm -1 ${{}^{-1}}$ in the visible part of the spectrum.