Zone-center phonons in yellow phase CsSnI3
نویسندگان
چکیده
The zone-center phonons are calculated for yellow phase CsSnI3 using density functional perturbation theory in a plane-wave pseudopotential method. The infrared absorption and reflection spectra are simulated and show that the absorption has a strong contribution from the LO as well as TO modes. The polarization-dependent Raman spectra for various configurations are simulated. The results for the Raman and the infrared reflection spectra are found to be in good agreement with the available experimental data when averaging over directions. The Born effective charges and highand low-frequency dielectric tensors are calculated. The ratio of the static to the high-frequency dielectric constants is high in the y direction.
منابع مشابه
Energy barrier at the N719-dye/CsSnI3 interface for photogenerated holes in dye-sensitized solar cells
This report is to address the question if black γ-polymorph of cesium tin tri-iodide (B-γ-CsSnI3) can be used as a solid-state hole-transport material in the conventional DSSCs with the N719 dye to replace the liquid electrolyte as reported by I. Chung et al. on Nature 485, 486, (2012). Here we demonstrate rigorously that B-γ-CsSnI3 is not energetically possible to collect photogenerated holes ...
متن کاملAb initio study of the electronic and structural properties of CsSnI3 perovskite
The CsSnI3 crystal belongs to an interesting class of semiconducting perovskite which is currently used in thin-film field-effect transistor made of organics-inorganics hybrid compounds. The benefit of using hybrid compounds resides in their ability to combine the advantage of these two classes of compounds: the high mobility of inorganic materials and the ease of processing of organic material...
متن کاملEnhanced polarization in strained BaTiO 3 from first principles
The structure, polarization, and zone-center phonons of bulk tetragonal BaTiO 3 under compressive epitaxial stress are calculated using density functional theory within the local density approximation. The polarization, computed using the Berry-phase formalism, increases with increasing tetragonality and is found to be enhanced by nearly 70% for the largest compressive misfit strain considered ...
متن کاملMultiphonon Raman scattering from individual single-walled carbon nanotubes.
Combinations of up to 6 zone-edge and zone-center optical phonons are observed in the Raman spectra of individual single-walled carbon nanotubes (SWNTs). These multiphonon Raman modes exhibit distinct signatures of the one-dimensional nature of SWNTs and provide information on the phonon structure, exciton-phonon coupling, and excitonic transitions in nanotubes.
متن کاملPhonon self-energy corrections to nonzero wave-vector phonon modes in single-layer graphene.
Phonon self-energy corrections have mostly been studied theoretically and experimentally for phonon modes with zone-center (q=0) wave vectors. Here, gate-modulated Raman scattering is used to study phonons of a single layer of graphene originating from a double-resonant Raman process with q≠0. The observed phonon renormalization effects are different from what is observed for the zone-center q=...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2017