Probing the effect of different exchange-correlation functionals on the optoelectronic features of chalcogenide compound Ag2O

Abstract

The primary goal of this study is to investigate the effect of different exchange-correlation functionals on the optoelectronic and elastic properties of the Ag2O chalcogenide compound. For the electronic structures and optical spectra, the Tran-Blaha modified Becke-Johnson approach combined with GGA and with GGA+U (mBJ-GGA-PBEsol and mBJ-GGA-PBEsol+U, respectively) was used. The available theoretical and experimental data for the bandgap energy were reported to determine whether there is a correlation with our results. The electronic structure revealed that our compound is a direct semiconductor at the R-symmetry point with a bandgap of 1.22 eV, which this value agrees well with the experimental values for the first time. The elastic constants were also evaluated using the IRelast package, which revealed that the compound was mechanically stable. Finally, the optical response was systematically studied, and it was found that Ag2O exhibited excellent optical efficiency.

A Density Functional Theory Exploration of Cs2B′B″I6 (B′B″: BeCa, BeSr, GeCd, GeBe, GeMg) Halide Double Perovskites for Optimal Solar Cell and Renewable Energy Applications

“…Negative values of ε 1 in the range of ≈9.0-13.0 eV for Cs 2 B 0 B 00 I 6 (B 0 B 00 : BeCa, GeCd, GeBe, GeMg) DPs and of 9.45596-13.0 eV for Cs 2 BeSrI 6 suggest a complete reflection of incident photons. [80][81][82][83] In Figure 5b, the imaginary part ε 2 displays the threshold energy about 2.7, 2.9, 1.1, 1.5, and 2.2 eV for Cs 2 B 0 B 00 I 6 (B 0 B 00 : BeCa, BeSr, GeCd, GeBe, GeMg) DPs, respectively, referring to the process where an electron is elevated from the VB to the CB. In Figure 5c, the refractive index (n) reveals static refractive index values (n(0)) of 1.85081, 1.78383, 2.25703, 2.33196, and 2.07519 for Cs 2 B 0 B 00 I 6 (B 0 B 00 : BeCa, BeSr, GeCd, GeBe, GeMg) DPs, respectively, as detailed in Table 4.…”