Investigating the electronic structure of confined multiexcitons with nonlinear spectroscopies

Abstract

Comparing the excited-state properties of a mixed-cation-mixed-halide perovskite to methylammonium lead iodide

Fifth-order two-quantum absorptive two-dimensional electronic spectroscopy of CdSe quantum dots

“…Under high pump intensity, ESA is diminished in band-edge TA spectra of CdSe QDs as the XX state becomes saturated. 37 The band-edge TA spectrum then resembles the linear absorption spectrum. 37,47 Experimental E 3 projections at t 2 = 100 fs and with a pulse energy of 35 nJ/pulse.…”

“…37 The band-edge TA spectrum then resembles the linear absorption spectrum. 37,47 Experimental E 3 projections at t 2 = 100 fs and with a pulse energy of 35 nJ/pulse. Spectra are normalized to their absolute maxima, which changes the sign of the 1Q spectrum.…”

“…These features have been discussed in more detail in previous publications. 37,38 Projections onto the emission axis, E 3 , reflect emission energies. All the third-order 1Q, fifth-order 1Q, and fifth-order 2Q pathways have 1Q coherences on the emission axis.…”

“…The sum of the k 1 − k 2 + k 3 and −k 1 + k 2 + k 3 signals gives a fully absorptive spectrum, as typically measured in 2D spectroscopies. [34][35][36][37] An example pathway is shown in the WMEL diagram in Fig. 1(a).…”

“…In this pathway, the first pulse interacts with the system three times, while the second and third pulses interact once each. These fifth-order 1Q signals can complicate the interpretation of 1Q spectra [37][38][39] and cannot be readily isolated from their third-order 1Q counterparts using phasecycling, though these contributions can be distinguished based on their pulse intensity dependence.…”