Photophysical Properties of SrTaO2N Thin Films and Influence of Anion Ordering: A Joint Theoretical and Experimental Investigation
Le Paven, Claire
Le Gendre, Laurent
Hedhili, Mohamed N.
Garcia-Esparza, Angel T.
Le Bahers, Tangui
KAUST DepartmentKAUST Catalysis Center (KCC)
Physical Sciences and Engineering (PSE) Division
Imaging and Characterization Core Lab
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AbstractConverting photon energy into chemical energy using inorganic materials requires the successful capture of photons, exciton dissociation, and the charge carrier diffusion. This study reports a thorough analysis of the optoelectronic properties of visible-light-responsive SrTaON perovskites to quantify their absorption coefficient and the generated charge carriers' effective masses, dielectric constants, and electronic structures. The measurements on such intrinsic properties were attempted using both epitaxial and polycrystalline SrTaON films deposited by radiofrequency magnetron sputtering under N reactive plasma. Density functional theory calculations using the HSE06 functional provided reliable values of these optoelectronic properties. Such quantities obtained by both measurements and calculations gave excellent correspondence and provide possible variations that account for the small discrepancies observed. One of the significant factors determining the optical properties was found to be the anion ordering in the perovskite structure imposed by the cations. As a result, the different anion ordering has a noticeable influence on the optical properties and high sensitivity of the hole effective mass. Determination of relative band positions with respect to the water redox properties was also attempted by Mott-Schottky analysis. All these results offer the opportunity to understand why SrTaON possesses intrinsically all the ingredients needed for an efficient water splitting device.
CitationZiani A, Le Paven C, Le Gendre L, Marlec F, Benzerga R, et al. (2017) Photophysical Properties of SrTaO2N Thin Films and Influence of Anion Ordering: A Joint Theoretical and Experimental Investigation. Chemistry of Materials 29: 3989–3998. Available: http://dx.doi.org/10.1021/acs.chemmater.7b00414.
SponsorsThe research reported in this work was supported by the King Abdullah University of Science and Technology.
PublisherAmerican Chemical Society (ACS)
JournalChemistry of Materials