A consistent picture of excitations in cubic BaSnO3 revealed by combining theory and experiment

Abstract Among the transparent conducting oxides, perovskite barium stannate is most promising for various electronic applications due to its outstanding carrier mobility achieved at room temperature. However, of important characteristics, such as band gaps, effective masses, and absorption edge, remain controversial. Here, we provide a fully consistent picture by combining state-of-the-art ab initio methodology with forefront electron energy-loss spectroscopy optical measurements. Valence spectra, featuring signals originating from gap transitions, are acquired on defect-free sample regions BaSnO 3 single crystal. These high-energy-resolution measurements able capture also very weak excitations below gap, attributed indirect transitions. By temperature-dependent measurements, assess band-gap renormalization effects induced electron-phonon coupling. Overall, find mass, direct well onsets excellent agreement between both experimental techniques theoretical many-body results, supporting phonon-mediated mechanism where transitions activated phonon-induced symmetry lowering. This work demonstrates fruitful connection different high-level methods exploring characteristics advanced materials.