Figure 5.

(A) Fluorescence-excitation (black) and emission (gray) spectra from an ensemble of LH2 complexes embedded in a PVA-film. (B) Summed fluorescence-excitation (black) and emission (gray) spectra from 74 LH2 complexes. For each complex the fluorescence-excitation/emission spectrum corresponds to the sum of all recorded individual scans/spectra for that complex as indicated in Fig. 2. (C) Summed fluorescence-excitation (black) and emission (gray) spectra from those 28 LH2 complexes for which an entire fluorescence-excitation spectrum has been recorded. For each complex the fluorescence-excitation/emission spectrum corresponds to the sum of all recorded individual scans/spectra for that complex as indicated in Fig. 2. (D) Summed fluorescence-excitation (black) and emission (gray) spectra from 21 (out of the previous 28) LH2 complexes. Here, for each complex only those individual fluorescence-excitation scans have been picked out from the spectral diffusion plots, for which no spectral overlap of the k = 0 and the higher exciton states occurred during the observation time due to spectral diffusion. For the summed emission spectrum only those emission spectra have been used, which showed an overlap with the k = 0 band in the corresponding fluorescence-excitation spectrum. Both types of spectra (fluorescence-excitation and emission) from each complex were first normalized and then summed up. All spectra are peak normalized and (A–C) have been offset for clarity. The data have been recorded at 1.2 K.