Slow Dynamics of the Photoinduced Phase Transition in Pd(dmit)₂Salts (dmit = 1,3-dithiol-2-thione-4,5-dithiolate)

Abstract

Slow dynamics of the initially photoinduced state has been observed by the pumpprobe type time-resolved reection spectroscopy in the charge separated phase of the half-lled strong dimer system, Et2Me2Sb[Pd(dmit)2]2 (dmit = 1,3-dithiol-2-thione-4,5-dithiolate). We have succeeded to reproduce the probe photon energy dependence of the time prole qualitatively in the time delay range from 10 ps to 1 ns assuming the dynamical expansion of the domain of the photo-induced dimer-Mott insulating phase in the host charge-separated one.

Time-Resolved Infrared Vibrational Spectroscopy of the Photoinduced Phase Transition of Pd(dmit)2 Salts Having Different Orders of Phase Transition

“…The details of the early dynamics of the Cs salt studied in terms of transient electronic spectra employing time-resolved near-infrared spectroscopy will be published elsewhere. 53 3.3. Photoinduced Phase Transition Vs Thermal Phase Transition.…”

“…In the Cs salt, a similar result was obtained. 53 However, we only observed changes in the electronic states of the dimer, which reflects the distance between the two molecules in the dimer. Thus, in the current study we investigated the hidden PIPT dynamics by the previous near-infrared spectroscopy method using timeresolved infrared vibrational spectroscopy in terms of variations in the structure and charge of the constituent molecules.…”

Photoinduced Phase Transition in Strongly Electron-Lattice and Electron–Electron Correlated Molecular Crystals

“…We consider that metastable state I at this stage is similar to the high-temperature DM phase with respect to the electronic or local structures of the Pd(dmit) 2 dimer; however, the crystal structure of the entire crystal is not exactly the same as the high-temperature phase corresponding to the nature of the system's thermal first-order phase transition [34]. After the time scale (~20 ps) in Figure 4, we found additional slow dynamics, which may be attributed to domain motion [37].…”

The photoinduced dynamics of X[M(dmit)2]2salts

“…According to this idea, we expect to observe a macroscopic phase change triggered by local photo-excitation. The photoinduced phase change was investigated using time-resolved optical spectroscopy [51].…”

“…We have recently succeeded in observing photoinduced dynamics in the charge-separated (CS) phase of M(dmit) 2 salts, which exhibit phase transitions to average-valence, high-temperature states using optical spectroscopy (M = Pd, Pt) [51][52][53] and electron diffraction (M = Pt) [53]. In the case of Pt(dmit) 2 , we were able to perform both spectroscopy and diffraction measurements under similar conditions and demonstrate full consistency of the data, which is necessary to make the connection between electronic and molecular dynamics.…”