Enhanced photocatalytic O2 activation by the synergy of efficient oxygen adsorption and interfacial charge separation: A case of Bi3O4Br/rGO van der Waals heterojunction

2022 ◽  
pp. 120416
Author(s):  
Jiaqi Hu ◽  
Fangyuan Chen ◽  
Kelei Mu ◽  
Jing Zhang ◽  
Jinfeng Lu
Keyword(s):  
Charge Separation ◽  
Van Der Waals ◽  
Oxygen Adsorption ◽  
O2 Activation ◽  
Interfacial Charge

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.

scholarly journals Efficient charge separation and visible-light response in bilayer HfS2-based van der Waals heterostructures

RSC Advances ◽  
2018 ◽  
Vol 8 (34) ◽  
pp. 18889-18895 ◽  
Author(s):  
Biao Wang ◽  
Xukai Luo ◽  
Junli Chang ◽  
Xiaorui Chen ◽  
Hongkuan Yuan ◽  
...  
Keyword(s):  
Charge Separation ◽  
Density Functional ◽  
Van Der Waals ◽  
Light Response ◽  
Hybrid Density Functional Theory ◽  
Functional Theory ◽  
Visible Light Response ◽  
Efficient Charge ◽  
Hybrid Density Functional ◽  
Photocatalytic Applications

In this work, we employ hybrid density functional theory to investigate HfS2-based van der Waals (vdW) heterojunctions for highly efficient photovoltaic and photocatalytic applications.

scholarly journals Mechanisms of Ultrafast Charge Separation in a PTB7/Monolayer MoS2 van der Waals Heterojunction

2018 ◽  
Vol 9 (10) ◽  
pp. 2484-2491 ◽  
Author(s):  
Chengmei Zhong ◽  
Vinod K. Sangwan ◽  
Chen Wang ◽  
Hadallia Bergeron ◽  
Mark C. Hersam ◽  
...  
Keyword(s):  
Charge Separation ◽  
Van Der Waals ◽  
Monolayer Mos2

scholarly journals Long-lived and disorder-free charge transfer states enable endothermic charge separation in efficient non-fullerene organic solar cells

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ture F. Hinrichsen ◽  
Christopher C. S. Chan ◽  
Chao Ma ◽  
David Paleček ◽  
Alexander Gillett ◽  
...  
Keyword(s):  
Solar Cells ◽  
Charge Transfer ◽  
Organic Solar Cells ◽  
Charge Separation ◽  
Free Charge ◽  
Charge Generation ◽  
Time Resolved ◽  
Thermodynamic Conditions ◽  
Donor Acceptor ◽  
Interfacial Charge

Abstract Organic solar cells based on non-fullerene acceptors can show high charge generation yields despite near-zero donor–acceptor energy offsets to drive charge separation and overcome the mutual Coulomb attraction between electron and hole. Here, we use time-resolved optical spectroscopy to show that free charges in these systems are generated by thermally activated dissociation of interfacial charge-transfer states that occurs over hundreds of picoseconds at room temperature, three orders of magnitude slower than comparable fullerene-based systems. Upon free electron–hole encounters at later times, both charge-transfer states and emissive excitons are regenerated, thus setting up an equilibrium between excitons, charge-transfer states and free charges. Our results suggest that the formation of long-lived and disorder-free charge-transfer states in these systems enables them to operate closely to quasi-thermodynamic conditions with no requirement for energy offsets to drive interfacial charge separation and achieve suppressed non-radiative recombination.

Modulating Charge Separation with Hexagonal Boron Nitride Mediation in Vertical Van der Waals Heterostructures

2020 ◽  
Vol 12 (23) ◽  
pp. 26213-26221 ◽  
Author(s):  
Christy Roshini Paul Inbaraj ◽  
Roshan Jesus Mathew ◽  
Rajesh Kumar Ulaganathan ◽  
Raman Sankar ◽  
Monika Kataria ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Charge Separation ◽  
Hexagonal Boron Nitride ◽  
Van Der Waals ◽  
Van Der Waals Heterostructures
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