The impressive rise in efficiencies of solar cells employing the three-dimensional (3D) lead-iodide perovskite absorbers APbI3 (A = monovalent cation) has generated intense excitement. Although these perovskites have remarkable properties as solar-cell absorbers, their potential commercialization now requires a greater focus on the materials' inherent shortcomings and environmental impact. This...

The electronic structure and optical absorption spectrum of organometal halide perovskite compound CH3NH3BiI3 as a substituting candidate of well-concerned CH3NH3PbI3 not only for environmental friendly consideration are studied using the first principles calculations. It is revealed that a Bi replacement of Pb in CH3NH3PbI3 does not change seriously the band edge structure but the bandgap beco...

The surface enhanced Raman spectra of halide ions adsorbed on colloidal silver surfaces can be explained by an interacting dipole model of a discrete adsorbate superlattice. Both (100) and (111) surfaces have been modeled, and simulated spectra for a range of adsorbate coverage fractions and sol particle facet sizes give good agreement with experimental spectra. The model is useful for assessin...

Halide perovskites show high photoluminescence quantum yields and tunable bandgap. While perovskites’ optical properties significantly degrade due to the ionic electronic defects, a correlation among their structure, size, degradation rate remains concealed. The authors report crystal shape- halide vacancy-dependent stability of methylammonium lead bromide single crystals. vacancies are filled ...

8 The properties of a halogen-covered platinum (111) surface have been studied using density func9 tional theory (DFT) as halides are often present at electrochemical electrode/electrolyte interfaces. 10 We focused in particular on the halogen-induced work function change as a function of coverage 11 of fluorine, chlorine, bromine and iodine. For electronegative adsorbates, an adsorption-induce...

Information on the energy of 5d levels of Ce in chloride, bromide, and iodide compounds has been collected. From this, values for the centroid shift and the crystal field splitting of the 5d configuration are obtained. The centroid shift will be related to the polarizability of the anions and further analyzed by means of the ligand polarization model. The crystal field splitting is to a large e...

Radiative recombination in thin films of the archetypical, high-performing perovskites CH3NH3PbBr3 and CH3NH3PbI3 shows localized regions of increased emission with dimensions ≈500 nm. Maps of the spectral emission line shape show narrower emission lines in high emission regions, which can be attributed to increased order. Excited states do not diffuse out of high emission regions before they d...