Unambiguous determination of hot-electron two-temperature dynamics from transfer-matrix retrieval

Ascertain unambiguously, by directly retrieving dynamics from axially-resolved transfer-matrix analysis of transient reflectance, whether hot electrons in the silver films of metal–organic optical microcavities follow a two-temperature relaxation model and determine their characteristic time constants, overcoming current noise limitations.

Background

The paper incorporated pump-induced refractive-index changes in both the organic and metal layers and achieved high-quality fits to the measured differential reflectance using transfer-matrix simulations. While this established a substantial absorptive contribution from the metal films, extracting the temporal evolution of hot-electron populations directly from the transfer-matrix retrieval was hampered by noise.

Because direct retrieval was inconclusive, the authors turned to statistical correlation analyses to support the presence of hot electrons with two-temperature dynamics. A direct, unambiguous determination of the two-temperature behavior from transfer-matrix-based dynamics remains outstanding.

References

Lastly, the large noise in the TM-retrieved dynamics (Supplementary material, Fig.~S31) prevented us from the unambiguous determination of hot electrons evolving in accordance with a two-temperature model where the majority of the dynamics occurs within the first time constant ($\sim$1~ps, electron-electron scattering) and the rest of the dynamics occurs within the second time-constant ($\sim$10~ps, electron-phonon scattering).

— Dark excitons and hot electrons modulate exciton-photon strong coupling in metal-organic optical microcavities (2401.14835 - Kolesnichenko et al., 26 Jan 2024) in Section “Strong-coupling optical effects of dark excitons and hot electrons,” end of subsection