Spectral hold burning in the Soret absorption band of a zinc tetrabenzoporphin derivative

The results of photon-gated spectral hole burning in the Soret absorption band of a Zn tetrabenzoporphin derivative in poly(methylmethacrylate) are reported. Zero-photon holes are formed throughout the whole Soret band via the photon-gating technique. The electron-photon coupling in both the first S1 and second S2 excited singlet states is shown to be approximately equal; the Huang-Rhys factor is 0.3. The zero-phonon holewidth yields an S2 state lifetime of 1.7 ps at 20 K. A strong correlation between S0S1 and S0S2 transitions was observed with the correlation coefficient ϱ = 0.981.