Metal-ion dependent band energetics in SrM0.5Ti0.5O3 (M =Ru, Rh, Ir, Pt, Pd) like structures for solar applications
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We present here a detailed comparative study of the theoretically-calculated electronic structures of the cubic Sr M0.5Ti0.5O3(M: Ru, Rh, Ir, Pt, Pd) type and SrTiO3 system. A their full potential linearized augmented plane wave (FP-LAPW) method was used to obtain its band structure within the framework of a density functional theory by using Wien97 code. The 4d orbitals of Ru, Rh and 5d orbitals of Ir, Pt respectively, contribute to the top of the valence band yielding a band gap narrowing of cubic SrTiO3. The computed tolerance factor for the SrTi0.5Pd0.5O3 perovskite structure indicates an unstable structural formation with Pd metal ion. The computation of the frequency-dependent absorption coefficient I(ω) of SrTi0.5M0.5O3indicates that Rh has a significant absorption efficiency for low energy (E ≤ 2ev) photons, whereas Ru and Ir display a very high absorption efficiency for photons with E > 2eV. Theoretical prediction validates that Rh can yield a better solar photoactive material than Ru and Ir in the SrTi0.5M0.5O3 (M:Ru, Rh, Ir) type system for low energy photon applications.
Abstract
We present here a detailed comparative study of the theoretically-calculated electronic structures of the cubic Sr M0.5Ti0.5O3(M: Ru, Rh, Ir, Pt, Pd) type and SrTiO3 system. A their full potential linearized augmented plane wave (FP-LAPW) method was used to obtain its band structure within the framework of a density functional theory by using Wien97 code. The 4d orbitals of Ru, Rh and 5d orbitals of Ir, Pt respectively, contribute to the top of the valence band yielding a band gap narrowing of cubic SrTiO3. The computed tolerance factor for the SrTi0.5Pd0.5O3 perovskite structure indicates an unstable structural formation with Pd metal ion. The computation of the frequency-dependent absorption coefficient I(ω) of SrTi0.5M0.5O3indicates that Rh has a significant absorption efficiency for low energy (E ≤ 2ev) photons, whereas Ru and Ir display a very high absorption efficiency for photons with E > 2eV. Theoretical prediction validates that Rh can yield a better solar photoactive material than Ru and Ir in the SrTi0.5M0.5O3 (M:Ru, Rh, Ir) type system for low energy photon applications.
참고문헌 (12)
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