RESUMEN
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 1.1-1.5â 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.
RESUMEN
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.
RESUMEN
Long-term indoor radon measurements performed by LR 115 track etched detectors in Croatian homes during 2003-04 showed that the arithmetic means of radon concentrations in Lika-Senj and the southern part of Karlovac counties were three times higher (198 Bq m(-3)) than in houses at national level (68 Bq m(-3)). Recently, indoor radon measurements in randomly selected houses were investigated. The obtained values in these new measurements have confirmed the values obtained 10 y ago (the average radon value in 225 investigated houses in this area is 223 Bq m(-3)). Radon concentrations in soil gas were measured in September and October 2012 and 2013 with the AlphaGUARD measuring system. Areas with both elevated indoor radon levels and radon in soil gas were identified (some micro locations in Korenica, Licko Lesce, Generalski Stol, Slunj and Ogulin) and visually presented in the form of maps using the inverse distance weighting approach.