Charge‐Transfer Exciton State and Energy Levels in Tetracene Crystal

1965 ◽  
Vol 43 (9) ◽  
pp. 3367-3371 ◽  
Author(s):  
Martin Pope ◽  
José Burgos ◽  
Joseph Giachino
Keyword(s):  
Charge Transfer ◽  
Energy Levels ◽  
Exciton State

scholarly journals Asymmetry in Charge Transfer Pathways Caused by Pigment–Protein Interactions in the Photosystem II Reaction Center Complex

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 718
Author(s):  
Yoshihiro Sato ◽  
Danielle Sicotte
Keyword(s):  
Charge Transfer ◽  
Photosystem Ii ◽  
Reaction Center ◽  
Protein Interactions ◽  
Energy Levels ◽  
Tight Binding ◽  
Relative Displacement ◽  
Primary Charge Separation ◽  
Binding Model ◽  
Reaction Center Complex

This article discusses the photoinduced charge transfer (CT) kinetics within the reaction center complex of photosystem II (PSII RC). The PSII RC exhibits a structural symmetry in its arrangement of pigments forming two prominent branches, D1 and D2. Despite this symmetry, the CT has been observed to occur exclusively in the D1 branch. The mechanism to realize such functional asymmetry is yet to be understood. To approach this matter, we applied the theoretical tight-binding model of pigment excitations and simulated CT dynamics based upon the framework of an open quantum system. This simulation used a recently developed method of computation based on the quasi-adiabatic propagator path integral. A quantum CT state is found to be dynamically active when its site energy is resonant with the exciton energies of the PSII RC, regardless of the excitonic landscape we utilized. Through our investigation, it was found that the relative displacement between the local molecular energy levels of pigments can play a crucial role in realizing this resonance and therefore greatly affects the CT asymmetry in the PSII RC. Using this mechanism phenomenologically, we demonstrate that a near 100-to-1 ratio of reduction between the pheophytins in the D1 and D2 branches can be realized at both 77 K and 300 K. Our results indicate that the chlorophyll Chl D 1 is the most active precursor of the primary charge separation in the D1 branch and that the reduction of the pheophytins can occur within pico-seconds. Additionally, a broad resonance of the active CT state implies that a large static disorder observed in the CT state originates in the fluctuations of the relative displacements between the local molecular energy levels of the pigments in the PSII RC.

π-Bridge modification of thiazole-bridged DPP polymers for high performance near-IR OSCs

2018 ◽  
Vol 20 (3) ◽  
pp. 1664-1672 ◽  
Author(s):  
Kuangshi Sun ◽  
Xiaoqin Tang ◽  
Yalin Ran ◽  
Rongxing He ◽  
Wei Shen ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Charge Transport ◽  
Transport Properties ◽  
High Performance ◽  
Intramolecular Charge Transfer ◽  
Energy Levels ◽  
Near Ir

π-Bridge modification could adjust the molecular energy levels and improve the optical, intramolecular charge transfer and charge transport properties.

scholarly journals Configuration coordinate energy level diagrams of intervalence and metal-to-metal charge transfer states of dopant pairs in solids

2015 ◽  
Vol 17 (30) ◽  
pp. 19874-19884 ◽  
Author(s):  
Zoila Barandiarán ◽  
Andries Meijerink ◽  
Luis Seijo
Keyword(s):  
Charge Transfer ◽  
Energy Level ◽  
Energy Levels ◽  
Mixed Valence ◽  
Active Centers ◽  
Metal Charge ◽  
Intervalence Charge Transfer ◽  
Metal Charge Transfer ◽  
Configuration Coordinate

Configuration coordinate diagrams, which are normally used in a qualitative manner for the energy levels of active centers in phosphors, are quantitatively obtained here for intervalence charge transfer (IVCT) states of mixed valence pairs and metal-to-metal charge transfer (MMCT) states of heteronuclear pairs, in solid hosts.

Synthesis of a new W-type of functional polymer for improving intermolecular charge transfer processes at donor/acceptor interfaces

2019 ◽  
Vol 31 (5) ◽  
pp. 521-527 ◽  
Author(s):  
Yun-Fan Zhang ◽  
Fawen Wu
Keyword(s):  
Charge Transfer ◽  
Energy Gap ◽  
Energy Levels ◽  
Coupling Reaction ◽  
Photocurrent Density ◽  
Orbital Energy ◽  
Functional Polymer ◽  
Suzuki Coupling Reaction ◽  
Donor Acceptor ◽  
Lowest Unoccupied Molecular Orbital

Optimizing charge transfer (CT) processes at donor/acceptor interfaces is an important subject to improving photocurrent density. Geometries of functional polymers play important roles in design of new types of polymers, which were used as electron donor to improve effective separation of electron-hole pairs at donor/acceptor interfaces. In this article, a novel W-type of polymer, poly(1-[4-(9-(2-ethylhexyl)carbazole-3-yl)]phenylazo-2-phenylazoacenaphthylene), was synthesized by a Suzuki coupling reaction for improving interaction between polymers and electron acceptors to enhance intermolecular CT. Geometry of combination of the polymer and C60 shows that main-chain of the polymer could sufficiently touch C60 derivatives. The polymer exhibited a broadband light absorption at the wavelength range from 250 to 650 nm. Ultraviolet–visible spectra and cyclic voltammetry curve suggest that the highest occupied, lowest unoccupied molecular orbital energy levels, and energy gap values are −5.09, −3.18 and 1.91 eV. Fluorescence quenching experiments shows that 99.9% of emission fluorescence of the polymer was quenched by added C60. Therefore, excited electrons at the polymer would be completely transferred to C60 molecules. This article suggests a new W-type functional polymer for improving intermolecular CT processes at donor/acceptor interfaces.

Singlet state energy levels of C2H2+4 by double charge transfer spectroscopy

1993 ◽  
Vol 178 (1-3) ◽  
pp. 581-590 ◽  
Author(s):  
P.G. Fournier ◽  
J. Fournier ◽  
M.L. Langford ◽  
F.M. Harris
Keyword(s):  
Charge Transfer ◽  
State Energy ◽  
Singlet State ◽  
Energy Levels ◽  
Double Charge
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