Ultrafast, asymmetric charge transfer and slow charge recombination in porphyrin/CNT composites demonstrated by time-domain atomistic simulation

Nanoscale ◽  
2018 ◽  
Vol 10 (26) ◽  
pp. 12683-12694 ◽  
Author(s):  
Ritabrata Sarkar ◽  
Md Habib ◽  
Sougata Pal ◽  
Oleg V. Prezhdo
Keyword(s):  
Charge Transfer ◽  
Time Domain ◽  
Charge Separation ◽  
Atomistic Simulation ◽  
Charge Recombination

Defect-free porphyrin/CNT hybrids can maintain long-lived charge separation; porphyrins and CNTs can be used to harvest light at different wavelengths.

scholarly journals How can infra-red excitation both accelerate and slow charge transfer in the same molecule?

2018 ◽  
Vol 9 (30) ◽  
pp. 6395-6405 ◽  
Author(s):  
Zheng Ma ◽  
Zhiwei Lin ◽  
Candace M. Lawrence ◽  
Igor V. Rubtsov ◽  
Panayiotis Antoniou ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Charge Separation ◽  
Charge Recombination ◽  
Recombination Rates ◽  
Infra Red ◽  
Induced Changes

A UV-IR-Vis 3-pulse study of infra-red induced changes to electron transfer (ET) rates in a donor–bridge–acceptor species finds that charge-separation rates are slowed, while charge-recombination rates are accelerated as a result of IR excitation during the reaction.

Ferroelastic domains drive charge separation and suppress electron–hole recombination in all-inorganic halide perovskites: time-domain ab initio analysis

2020 ◽  
Vol 5 (4) ◽  
pp. 683-690 ◽  
Author(s):  
Ran Shi ◽  
Zhaosheng Zhang ◽  
Wei-hai Fang ◽  
Run Long
Keyword(s):  
Ab Initio ◽  
Time Domain ◽  
Charge Separation ◽  
Charge Recombination ◽  
Electron Hole ◽  
Nonadiabatic Coupling ◽  
Halide Perovskites ◽  
Ferroelastic Domains ◽  
Hole Recombination

CsPbBr3 perovskites containing ferroelastic domains inhibit non-radiative charge recombination by facilitating charge separation and decreasing nonadiabatic coupling.

Spin Orbit Coupling in Orthogonal Charge Transfer States: (TD-)DFT of Pyrene - Dimethylaniline

2021 ◽  
Author(s):  
Shivan Bissesar ◽  
Davita M. E. van Raamsdonk ◽  
Dáire J. Gibbons ◽  
René M. Williams
Keyword(s):  
Charge Transfer ◽  
Charge Separation ◽  
Density Functional ◽  
Charge Recombination ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Td Dft ◽  
The Matrix ◽  
Initial Charge

The conformational dependence of the matrix element for spin-orbit coupling and of the electronic coupling for charge separation are determined for an electron donor-acceptor system containing a pyrene acceptor and a dimethylaniline donor. Different kinetic and energetic aspects that play a role in the spin-orbit charge transfer intersystem crossing (SOCT-ISC) mechanism are discussed. This includes parameters related to initial charge separation and the charge recombination pathways using the (Semi-Classical) Marcus Theory for electron transfer. The spin-orbit coupling, which plays a significant role in charge recombination to the triplet state can be probed by (TD-)DFT, using the latter as a tool to understand and predict the SOCT-ISC mechanism. The matrix elements for spin-orbit coupling for acetone and 4-thio-thymine are used for benchmarking. (Time Dependent-) Density Functional Theory (DFT and TD-DFT) calculations are applied using the quantum chemical program Amsterdam Density Functional (ADF).

Charge separation, charge recombination, long-lived charge transfer state formation and intersystem crossing in organic electron donor/acceptor dyads

2019 ◽  
Vol 7 (39) ◽  
pp. 12048-12074 ◽  
Author(s):  
Yuqi Hou ◽  
Xue Zhang ◽  
Kepeng Chen ◽  
Dongyi Liu ◽  
Zhijia Wang ◽  
...  
Keyword(s):  
Charge Transfer ◽  
State Formation ◽  
Charge Separation ◽  
Charge Recombination ◽  
Charge Transfer State ◽  
Intersystem Crossing ◽  
Organic Electron ◽  
Recent Developments ◽  
Donor Acceptor ◽  
Transfer State

The recent developments in charge separation, long-lived charge transfer state formation and charge recombination-induced intersystem crossing are summarized.

scholarly journals Spin Orbit Coupling in Orthogonal Charge Transfer States: (TD-)DFT of Pyrene - Dimethylaniline

2021 ◽  
Author(s):  
Shivan Bissesar ◽  
Davita M. E. van Raamsdonk ◽  
Dáire J. Gibbons ◽  
René M. Williams
Keyword(s):  
Charge Transfer ◽  
Charge Separation ◽  
Density Functional ◽  
Charge Recombination ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Td Dft ◽  
The Matrix ◽  
Initial Charge

The conformational dependence of the matrix element for spin-orbit coupling and of the electronic coupling for charge separation are determined for an electron donor-acceptor system containing a pyrene acceptor and a dimethylaniline donor. Different kinetic and energetic aspects that play a role in the spin-orbit charge transfer intersystem crossing (SOCT-ISC) mechanism are discussed. This includes parameters related to initial charge separation and the charge recombination pathways using the (Semi-Classical) Marcus Theory for electron transfer. The spin-orbit coupling, which plays a significant role in charge recombination to the triplet state can be probed by (TD-)DFT, using the latter as a tool to understand and predict the SOCT-ISC mechanism. The matrix elements for spin-orbit coupling for acetone and 4-thio-thymine are used for benchmarking. (Time Dependent-) Density Functional Theory (DFT and TD-DFT) calculations are applied using the quantum chemical program Amsterdam Density Functional (ADF).

scholarly journals Anion-enhanced excited state charge separation in a spiro-locked N-heterocycle-fused push-pull zinc porphyrin

2021 ◽  
Author(s):  
Mandeep K. Chahal ◽  
Anuradha Liyanage ◽  
Ajyal Z. Alsaleh ◽  
Paul A. Karr ◽  
Jonathan P. Hill ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Charge Separation ◽  
Charge Transfer Complex ◽  
Zinc Porphyrin ◽  
New Type ◽  
State Charge

A new type of push–pull charge transfer complex, viz., a spiro-locked N-heterocycle-fused zinc porphyrin, ZnP-SQ, is shown to undergo excited state charge separation, which is enhanced by axial F− binding to the Zn center.

scholarly journals Long-lived charge separation following pump-wavelength–dependent ultrafast charge transfer in graphene/WS2 heterostructures

2021 ◽  
Vol 7 (9) ◽  
pp. eabd9061
Author(s):  
Shuai Fu ◽  
Indy du Fossé ◽  
Xiaoyu Jia ◽  
Jingyin Xu ◽  
Xiaoqing Yu ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Charge Separation ◽  
Transient Absorption ◽  
Transition Metal Dichalcogenides ◽  
Thermionic Emission ◽  
Great Promise ◽  
Metal Dichalcogenides ◽  
Ultrafast Charge Transfer ◽  
Device Operation ◽  
Interfacial Charge

Van der Waals heterostructures consisting of graphene and transition metal dichalcogenides have shown great promise for optoelectronic applications. However, an in-depth understanding of the critical processes for device operation, namely, interfacial charge transfer (CT) and recombination, has so far remained elusive. Here, we investigate these processes in graphene-WS2 heterostructures by complementarily probing the ultrafast terahertz photoconductivity in graphene and the transient absorption dynamics in WS2 following photoexcitation. We observe that separated charges in the heterostructure following CT live extremely long: beyond 1 ns, in contrast to ~1 ps charge separation reported in previous studies. This leads to efficient photogating of graphene. Furthermore, for the CT process across graphene-WS2 interfaces, we find that it occurs via photo-thermionic emission for sub-A-exciton excitations and direct hole transfer from WS2 to the valence band of graphene for above-A-exciton excitations. These findings provide insights to further optimize the performance of optoelectronic devices, in particular photodetection.

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