Photocurrent generation enhanced by charge delocalization over stacked perylenediimide chromophores assembled within DNA.
We now report the photocurrent generation and charge transfer dynamics of stacked perylenediimide (PDI) molecules within a π-stack array of DNA. The cofacially stacked PDI dimer and trimer were found to strongly enhance the photocurrent generation compared to an isolated PDI monomer. Femtosecond time-resolved transient absorption experiments revealed that the excitation of the stacked PDI dimer and trimer provided the broad transient absorption band, which was attributed to the charge delocalization of a negative charge over the PDI chromophores. The lifetime of the charge delocalization of the PDI dimer and trimer (nearly 1 ns) was much longer than that of the charge separated state of the PDI monomer. A comparison between the photocurrent measurements and time-resolved transient absorption measurements demonstrated that the cofacially stacked structure could possibly lead to the charge delocalization and increase the lifetime of the charge-separated state that is essential to enhancing the photocurrent generation.
Department of Materials Science and Chemistry, Graduate School of Engineering, University of Hyogo , 2167 Shosha, Himeji, Hyogo 671-2280, Japan.
Tadao
T
Takada
Akane
A
Ashida
Mitsunobu
M
Nakamura
Mamoru
M
Fujitsuka
Tetsuro
T
Majima
Kazushige
K
Yamana
D001483:Base Sequence; D004396:Coloring Agents / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D019281:Dimerization; D004560:Electricity; D004583:Electrons; D007094:Imides / Q000737:chemistry*; D008958:Models, Molecular; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry; D055668:Photochemical Processes
D004396:Coloring Agents; D007094:Imides; C521332:perylenediimide; D010569:Perylene; D004247:DNA