First principles study on copper and iridium co-doped SrTiO3 for shifting the optical absorption into visible region

Abstract

Density functional theory (DFT) investigation is performed to observe the opto-electronic properties of iridium and copper co-doped structure of Pristine SrTiO 3 (Cubic Perovskite). Results suggest that copper and iridium co-doped structure of SrTiO 3 has significant absorption in visible region of the spectrum, which is a result of red shift phenomenon in the wavelength range 400-750 nm observed in this structure. However, in individual copper and iridium structures the optical absorption is mainly in ultraviolet (UV) region which limits its use in light-based devices and applications. The shift in absorption from UV to visible region in the co-doped structure extracts the maximum utilization of solar light and finds wide range of optical applications like solar cells. Refractive index and dielectric constants were also calculated and their peak values were found to be in correlation with the peaks in absorption spectrum.

Effect of Sr and Ti substitutions on optical and photocatalytic properties of Bi1−xSrxFe1−xTixO3 nanomaterials

“…The STO composition is observed to present a strong absorption in the UV region, with a negligible absorption for energies inferior to 3 eV, which is in good agreement with previously reported values. 42 For the BFO system, a first absorption edge is observed near 2.9 eV (⁓430 nm), originating from the transition from O 2p (VB) to Fe 3d (CB) orbitals, which further increases in the UV region. Note that, the substituted composition presents the highest absorption in the visible light region (1.77 -3.26 eV) compared to BFO and STO, which corroborates with our experimental results (figure 5c).…”

New Insights into Crystal Defects, Oxygen Vacancies, and Phase Transition of Ir-TiO2

“…The electron conductivity of TiO 2 could be enhanced as the Ir states cross the Fermi level . First-principles calculation revealed that the absorption edge of TiO 2 could be extended toward the visible region by Ir doping, due to its distinctive electronic structure. , …”

“…16 First-principles calculation revealed that the absorption edge of TiO 2 could be extended toward the visible region by Ir doping, due to its distinctive electronic structure. 17,18 In the recent years, the activity of Ir-doped TiO 2 (Ir-TiO 2 ) has been studied for hydrogen production, 15,19 remediation of gas pollutants, 20,21 photo-electrochemical sensing, 22 carbon dioxide reduction, 23 and antimicrobial activity. 24 All these studies indicate that Ir doping is beneficial to maximize the activity of TiO 2 , through an enhanced electron−hole separation.…”