Vibrational dynamics in lead halide hybrid perovskites investigated by Raman spectroscopy

Abstract

The effect of the incorporation of Cs+ and Br− in FAPbl3 investigated by Raman spectroscopy.

Raman spectroscopy insights into the α- and δ-phases of formamidinium lead iodide (FAPbI3)

“…A recent study by Ibaceta-Jaña et al made use of DFT simulations to calculate the expected Raman modes of α-FAPbI 3 , in addition to producing the crystals to compare their predictions to an experimental data set. 46 Their spectrum of the α-FAPbI 3 shows a peak at 114 cm −1 with a shoulder at 96 cm −1 , which match closely to the δ-FAPbI 3 spectrum recorded in this study. This suggests that Ibaceta-Jaña's spectrum may be due to the presence of some δ-phase coexisting with the α-phase, which has led to their misjudgement in the phase determination.…”

Tailored Lattice “Tape” to Confine Tensile Interface for 11.08%‐Efficiency All‐Inorganic CsPbBr3 Perovskite Solar Cell with an Ultrahigh Voltage of 1.702 V

“…In theory, the vibrational mode around 309 cm −1 in Raman spectra presents the reorientation of Cs + in CsPbBr 3 lattice influenced by the PbBr 6 octahedral framework, which is strongly dependent on the lattice strain. [ 46 , 47 ] The enlarged lattice allows for a blue shift of Raman peak under the presence of tensile strain. [ 48 ] Therefore, the pristine CsPbBr 3 perovskite film suffers from a serious tensile strain owing to the lower average wavenumber around 295 cm −1 for Cs + vibrational mode in Figure 3c , which is mainly formed during the annealing process owing to the different thermal expansion coefficients of adjacent layers in the PSC devices.…”

Vibrational study of lead bromide perovskite materials with variable cations based on Raman spectroscopy and density functional theory

“…The weaker polarization and planar structure of FA + results in an out-of-plane vibration without significant interactions with the surrounding sublattice PbX 6. [26,52] Figure 7c-e show the ESPs of the interactions between MA + , FA + , and Cs + with Br À , respectively. One finds that Cs + more strongly binds with Br À than MA + and FA + .…”