Effect of Electron(Hole)-Confined Longitudinal Optical Phonon Interactions on the Exciton Binding Energy in Quantum-Well Wires

Abstract

We have calculated the effect of the electron(hole)±confined LO-phonon interactions on the exciton binding energy in rectangular quantum-well wires (QWW) as a function of the length of one side of the wire for several values of the length of the other side. Our results indicate that the polaronic contribution to the binding increases as the confinement length increases.

Layer-Dependent Coherent Acoustic Phonons in Two-Dimensional Ruddlesden–Popper Perovskite Crystals

“…At very early delays, the photoinduced TR signal of the 2D RP perovskite crystals decays with an average time of 1.5–8 ps, which can be attributed to the relaxation of the hot carriers associated with LO phonons. The TR signal of (PEA) 2 PbI 4 decays faster than that of (EA) 2 PbI 4 (1.5 ps vs 5.5 ps) because the larger exciton binding energy of the PEA-linked 2D crystal promotes the release of the LO at a faster rate. , Therefore, the slower LO phonon emission rate with increasing number of inorganic layers is due to decreased exciton binding energy. , The observed TR oscillation can be attributed to the propagation of the CLAPs inside of the crystal lattice. ,,, The amplitude difference of the TR signal is due to the relative contribution of the thermoelastic properties and the deformation potential (DP) values of the perovskite crystals …”