scholarly journals Charge-transfer biexciton annihilation in a donor–acceptor co-crystal yields high-energy long-lived charge carriers

2020 ◽  
Vol 11 (35) ◽  
pp. 9532-9541
Author(s):  
Itai Schlesinger ◽  
Natalia E. Powers-Riggs ◽  
Jenna L. Logsdon ◽  
Yue Qi ◽  
Stephen A. Miller ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Transient Absorption ◽  
High Energy ◽  
Charge Carriers ◽  
One Dimensional ◽  
Femtosecond Transient Absorption ◽  
Donor Acceptor ◽  
Charge Transfer Excitons

Femtosecond transient absorption microscopy of donor–acceptor single co-crystals shows that photogenerated charge transfer excitons in one-dimensional donor–acceptor π stacks annihilate to produce high-energy, long-lived electrons and holes.

Synergistic doping effects of a ZnO:N/BiVO4:Mo bunched nanorod array photoanode for enhancing charge transfer and carrier density in photoelectrochemical systems

Nanoscale ◽  
2018 ◽  
Vol 10 (43) ◽  
pp. 20256-20265 ◽  
Author(s):  
Donghyung Kim ◽  
Zhuo Zhang ◽  
Kijung Yong
Keyword(s):  
Charge Transfer ◽  
Carrier Density ◽  
Nanorod Array ◽  
Charge Carriers ◽  
One Dimensional ◽  
Doping Effects

One-dimensional heterojunction nanorods are highly attractive as photoanodes for developing efficient photoelectrochemical (PEC) systems for the effective photogeneration of charge carriers and transport.

scholarly journals Mechanisms of triplet energy transfer across the inorganic nanocrystal/organic molecule interface

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiao Luo ◽  
Yaoyao Han ◽  
Zongwei Chen ◽  
Yulu Li ◽  
Guijie Liang ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Charge Transfer ◽  
Organic Molecule ◽  
Transient Absorption ◽  
High Energy ◽  
Model Systems ◽  
Trap States ◽  
Triplet Energy ◽  
Surface Trap ◽  
Triplet Energy Transfer

AbstractThe mechanisms of triplet energy transfer across the inorganic nanocrystal/organic molecule interface remain poorly understood. Many seemingly contradictory results have been reported, mainly because of the complicated trap states characteristic of inorganic semiconductors and the ill-defined relative energetics between semiconductors and molecules used in these studies. Here we clarify the transfer mechanisms by performing combined transient absorption and photoluminescence measurements, both with sub-picosecond time resolution, on model systems comprising lead halide perovskite nanocrystals with very low surface trap densities as the triplet donor and polyacenes which either favour or prohibit charge transfer as the triplet acceptors. Hole transfer from nanocrystals to tetracene is energetically favoured, and hence triplet transfer proceeds via a charge separated state. In contrast, charge transfer to naphthalene is energetically unfavourable and spectroscopy shows direct triplet transfer from nanocrystals to naphthalene; nonetheless, this “direct” process could also be mediated by a high-energy, virtual charge-transfer state.

EXCITONS IN QUASI-ONE-DIMENSIONAL CRYSTALLINE PERYLENE DERIVATIVES: BAND STRUCTURE AND RELAXATION DYNAMICS

2001 ◽  
Vol 15 (28n30) ◽  
pp. 3597-3600
Author(s):  
M. HOFFMANN ◽  
T. HASCHE ◽  
K. SCHMIDT ◽  
T. W. CANZLER ◽  
V. M. AGRANOVICH ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Band Structure ◽  
Quantum Chemical ◽  
Relaxation Dynamics ◽  
Charge Transfer Transition ◽  
Transition Dipole ◽  
One Dimensional ◽  
Perylene Derivatives ◽  
Charge Transfer Excitons ◽  
Fitting Parameters

The exciton structure of crystalline MePTCDI (N-N'-dimethylperylene-3,4,9,10-dicarboximide) is modeled by a one-dimensional Hamiltonian, which includes the interactions between Frenkel excitons with several vibronic levels and charge-transfer excitons. Using appropriate fitting parameters, which are verified by quantum chemical calculations, this model can explain the main features of the low temperature absorption spectrum. Polarized absorption spectra show different polarization ratios for the various peaks. This polarization behavior is explained by the varying contribution of the charge-transfer transition dipole, which has a direction different from the Frenkel transition dipole. Our model for the exciton band structure is supported by transient emission measurements.

scholarly journals Charge transfer excitons in a donor–acceptor amphidynamic crystal: the role of dipole orientational order

2020 ◽  
Vol 7 (11) ◽  
pp. 2951-2958
Author(s):  
Joshua W. R. Macdonald ◽  
Giacomo Piana ◽  
Massimiliano Comin ◽  
Elizabeth von Hauff ◽  
Gabriele Kociok-Köhn ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Large Amplitude ◽  
Orientational Order ◽  
Molecular Solids ◽  
Electrical Characteristics ◽  
Large Amplitude Motions ◽  
Donor Acceptor ◽  
Charge Transfer Excitons

Large amplitude motions in molecular solids are responsible for anomalous electrical characteristics in amphidynamic crystals. Here we explore the implications for charge transfer excitons photophysics.

Quadratic and Cubic Nonlinearities in Solution of Intramolecular Charge Transfer Aromatic Molecules A Quantum Two-Level Approach

1987 ◽  
Vol 109 ◽  
Author(s):  
M. Barzoukas ◽  
P. Fremaux ◽  
D. Josse ◽  
F. Kajzar ◽  
J. Zyss
Keyword(s):  
Charge Transfer ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Third Harmonic ◽  
One Dimensional ◽  
Aromatic Molecules ◽  
Donor Acceptor ◽  
Level Model ◽  
Quadratic And Cubic Nonlinearities ◽  
Two Level Model

ABSTRACTA two-level expression of the second-order hyperpolarizability (y) is proposed, and shown to contain a negative charge transfer (CT) contribution. Frequency dispersed measurements of the quadratic and cubic susceptibility of N-(4-nitropheny1)-L-prolinol (NPP), N-(4-nitrophenyl)-N-methylaminoacetonitrile (NPAN) and 2-(N-prolinol)-5-nitropyridine (PNP) are reported. The electric field induced second-harmonic generation (EFISH) and third-harmonic generation (THG) techniques in solution are used. A two-level model dispersion of y as from THG measurements is shown to lead to a neglegible electronic contribution to the overall EFISH nonlinearity, as compared to the orientational contribution. The theoretical β-components of these molecules, obtained consistently by finite-field and perturbational approaches, clearly confirm that the β-tensor is one-dimensional along the donor-acceptor CT axis. The off resonance quadratic polarizabilities (β) of these molecules are sequenced as follows : β(NPP)> β(PNP)> β(NPAN). However this increased efficiency is obtained at the expense of the transparency range.

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