Photoinduced electron transfer (PET) within D4–A and D–A photosynthetic systems: Enhanced intramolecular PET achieved by increasing the number of donors

Zhang, Xianfu; Zheng, Hongwei; Jin, Shuangming; Wang, Ruiyun

doi:10.1016/j.dyepig.2010.03.010

Cited by 9 publications

(2 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ultrafast spectroscopic techniques are powerful tools to investigate the photophysics occurring in the first few nanoseconds in the opto-electronic devices. Extensive works have been done to study the charge generation and recombination process in the photovoltaic devices. − In this paper, we use both femotosecond transient absorption and time-resolved fluorescence techniques to investigate the formation and recombination processes of the CT states in the D–A co-oligomers, F3T4-hP, F4T6-hP, and F5T8-hP. We first studied the solution state of the three D–A co-oligomers and then compared with their solid state.…”

Section: Introductionmentioning

confidence: 99%

Femtosecond Spectroscopic Study of Photoinduced Charge Separation and Recombination in the Donor–Acceptor Co-Oligomers for Solar Cells

Gao

Wang

et al. 2013

J. Phys. Chem. C

View full text Add to dashboard Cite

Femtosecond transient absorption and time-resolved fluorescence techniques are employed to study the formation and recombination processes of the charge transfer (CT) state in a series of liquid-crystalline conjugated donor–acceptor (D–A) co-oligomers F3T4-hP, F4T6-hP, and F5T8-hP. It is revealed that the CT state of the D–A co-oligomer film forms faster but recombines slower than that of its solution, which is beneficial for the charges to be extracted in the D–A co-oligomer-based photovoltaic cells. It is also found that all the films made from different D–A co-oligomers, different processing conditions, and the blend of the donor and acceptor moieties show exactly the same CT dynamics, even though the films show very different film morphologies and photovoltaic performances, which indicate that the CT state property is only decided by the intrinsic molecular nature but not the film morphologies. The film morphology only affects the charge transport process but does not affect the CT state formation and recombination processes.

show abstract

Section: Introductionmentioning

confidence: 99%

Femtosecond Spectroscopic Study of Photoinduced Charge Separation and Recombination in the Donor–Acceptor Co-Oligomers for Solar Cells

Gao

Wang

et al. 2013

J. Phys. Chem. C

View full text Add to dashboard Cite

show abstract

“…Pc molecules contain a planar π system and can be taken as tetraaza-tetrabenzo zinc porphyrins. They are good electron acceptors and frequently selected in artificial photosynthesis for several advantages, as shown by other researchers − and us: − (1) strong absorbing (ε max ≈ 3.0 × 10 5 M –1 cm –1 ) in the region of 600–800 nm where solar emission is the richest that reaches the earth surface, many model systems with small π-chromophores that are good for mechanism study are not actually competitive to the silicon solar cell, because they are not absorbing in the red region; (2) excellent stability to heat and light which is extremely important for the long lasting commercial use; (3) easy preparation with low cost starting materials; (4) redox properties and spectral characterization of anion radicals have been understood extensively. , Pc complexes are therefore quite possible to be practically utilized in the artificial photosynthetic systems. Hence evaluating the role of T 1 state of Pc in PET is important and also the purpose of this study.…”

Section: Introductionmentioning

confidence: 99%

Morpholine-Phthalocyanine (Donor–Acceptor) Construct: Photoinduced Intramolecular Electron Transfer and Triplet Formation from its Charge Separation State

Zhang

Wang

2011

J. Phys. Chem. A

Self Cite

View full text Add to dashboard Cite

Silicon phthalocyanine (SiPc) with two axially attached morpholine (MP) units was prepared, and its photophysics was studied by laser flash photolysis, steady state and time-resolved fluorescence methods. Both the fluorescence efficiency and lifetime of SiPc moiety were remarkably quenched, because of the efficient intramolecular photoinduced electron transfer (PET) from morpholine donors to SiPc moiety. The generated charge separation state (CSS), SiPc(•-)-MP(•+), which was observed by transient absorption spectra, showed a lifetime of 4.8 ns. The triplet quantum yield of SiPc unit in the supra-molecule is unexpectedly high, and the predominant spectral signal in microsecond-scale is triplet-triplet (T(1)-T(n)) absorption. This high triplet yield is due to the charge recombination of CSS that generates T(1) in 32% efficiency: SiPc(•-)-MP(•+) → (3)SiPc-MP. The T(1) formation process occurred efficiently because the CSS SiPc(•-)-MP(•+) has a higher energy (1.65 eV) than that of the triplet state (3)SiPc-MP (1.0 eV). Emission from the CSS was also observed: SiPc(•-)-MP(•+) → SiPc-MP + hν'.

show abstract

Fluorescence Properties of Phenol-Modified Zinc Phthalocyanine that Tuned by Photoinduced Intra-Molecular Electron Transfer and pH Values

Zhang

2011

J Fluoresc

View full text Add to dashboard Cite

Tetra[α-(4-hydroxyphenoxy)] zinc phthalocyanine, ZnPc(α-OPhOH)(4), was synthesized and its photophysics was found to be sharply pH dependent. Dual fluorescence emission around 700 nm was observed when it is dissolved in basic solution. The fluorescence of the phthalocyanine can be sharply switched off at pH 9.1 due to the intramolecular photoinduced electron transfer (PET) in ZnPc(α-OPhONa)(4), formed by the deprotonation of ZnPc(α-OPhOH)(4). The photophysics of both ZnPc(α-OPhOH)(4) and ZnPc(α-OPhONa)(4) were studied in detail by UV-vis absorption, steady state and time-resolved fluorescence and transient absorption (TA) to reveal the fluorescence quenching mechanism. Intra-molecular PET in ZnPc(α-OPhONa)(4) from the donor, PhONa subunits, to the acceptor, ZnPc moiety, was characterized by the much smaller fluorescence quantum yield (0.003) and lifetime (<0.20 ns). PET was further evidenced by the occurrence of charge separation state (CSS) in TA spectra, i.e. the bands due to anion radical of ZnPc and phenol radical. The lifetime of the charge separation state is ca. 3 ns, the efficiency of PET is ca. 99% and the rate constant of PET is 2.3 × 10(10) s(-1).

show abstract

Photoinduced electron transfer (PET) within D4–A and D–A photosynthetic systems: Enhanced intramolecular PET achieved by increasing the number of donors

Cited by 9 publications

References 16 publications

Femtosecond Spectroscopic Study of Photoinduced Charge Separation and Recombination in the Donor–Acceptor Co-Oligomers for Solar Cells

Femtosecond Spectroscopic Study of Photoinduced Charge Separation and Recombination in the Donor–Acceptor Co-Oligomers for Solar Cells

Morpholine-Phthalocyanine (Donor–Acceptor) Construct: Photoinduced Intramolecular Electron Transfer and Triplet Formation from its Charge Separation State

Fluorescence Properties of Phenol-Modified Zinc Phthalocyanine that Tuned by Photoinduced Intra-Molecular Electron Transfer and pH Values

Contact Info

Product

Resources

About