Light absorption optimizing in (La_0.25Bi_0.75)₂FeCrO₆ active layers: GGA + U study

An ab initio generalized gradient approximation study, plus Hubbard (U = 4.1 eV) correlation, of (La_0.25Bi_0.75)₂FeCrO₆ alloy, in the pnma structure/ferrimagnetic order of transition rare earth d-La electrons, shows an optimum optical absorption of about 10³ cm⁻¹ near an ideal bandgap around 1.52 eV, with local magnetic moments of (Cr³⁺, Fe³⁺) found to be (− 2.56, 4.14) μB, making it a promising candidate for photovoltaics and photoferroics. Tuned-gap La-Bi₂FeCrO₆ active layer should own enhanced light absorption and carrier mobility, could be suitable light absorbers, and should be an efficient alternative to many absorbers like wide-bandgap chalcopyrite for solar cells, failing to reach highest efficiency, or even compete with their metal–organic halide perovskite counterparts. (author)