Resolving multi-exciton generation by attosecond spectroscopy.
We propose an experimentally viable attosecond transient absorption spectroscopy scheme to resolve controversies regarding multiexciton (ME) generation in nanoscale systems. Absence of oscillations indicates that light excites single excitons, and MEs are created by incoherent impact ionization. An oscillation indicates the coherent mechanism, involving excitation of superpositions of single and MEs. The oscillation decay, ranging from 5 fs at ambient temperature to 20 fs at 100 K, gives the elastic exciton-phonon scattering time. The signal is best observed with multiple-cycle pump pulses.
A J
AJ
Neukirch
D M
DM
Neumark
M F
MF
Kling
O V
OV
Prezhdo
D004583:Electrons; D008027:Light; D009930:Organic Chemicals / Q000032:analysis; D013057:Spectrum Analysis / Q000379:methods*
D009930:Organic Chemicals; C057718:6-(Dimethylamino)-2-((1E,3E)-4-(4-(dimethylamino)phenyl)-1,3-butadien-1-yl)-1-ethylquinolinium perchlorate