scholarly journals Surface assembly of cobalt species for simultaneous acceleration of interfacial charge separation and catalytic reactions on Cd0.9Zn0.1S photocatalyst

2021 ◽  
Vol 42 (6) ◽  
pp. 1004-1012
Author(s):  
Khakemin Khan ◽  
Lifen Xu ◽  
Ming Shi ◽  
Jiangshan Qu ◽  
Xiaoping Tao ◽  
...  
2021 ◽  
Vol 7 (9) ◽  
pp. eabd9061
Author(s):  
Shuai Fu ◽  
Indy du Fossé ◽  
Xiaoyu Jia ◽  
Jingyin Xu ◽  
Xiaoqing Yu ◽  
...  

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.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ture F. Hinrichsen ◽  
Christopher C. S. Chan ◽  
Chao Ma ◽  
David Paleček ◽  
Alexander Gillett ◽  
...  

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.


2019 ◽  
Vol 131 (47) ◽  
pp. 16956-16961 ◽  
Author(s):  
Xingming Ning ◽  
Bingzhang Lu ◽  
Zhen Zhang ◽  
Peiyao Du ◽  
Hongxia Ren ◽  
...  

2017 ◽  
Vol 416 ◽  
pp. 666-671 ◽  
Author(s):  
Mei Yang ◽  
Qi Yang ◽  
Junbo Zhong ◽  
Shengtian Huang ◽  
Jianzhang Li ◽  
...  

2015 ◽  
Vol 91 (4) ◽  
Author(s):  
Soumya Bera ◽  
Nicolas Gheeraert ◽  
Simone Fratini ◽  
Sergio Ciuchi ◽  
Serge Florens

2014 ◽  
Vol 16 (13) ◽  
pp. 5922-5926 ◽  
Author(s):  
Ernest Pastor ◽  
Federico M. Pesci ◽  
Anna Reynal ◽  
Albertus D. Handoko ◽  
Mingjia Guo ◽  
...  

Transient absorption spectroscopy as a tool to monitor charge carriers in Cu2O–RuOx photocathodes for CO2 reduction.


2013 ◽  
Vol 117 (32) ◽  
pp. 7561-7570 ◽  
Author(s):  
Kaifeng Wu ◽  
Nianhui Song ◽  
Zheng Liu ◽  
Haiming Zhu ◽  
William Rodríguez-Córdoba ◽  
...  

2017 ◽  
Vol 8 ◽  
pp. 2640-2647 ◽  
Author(s):  
Xin Zhao ◽  
Zhong Chen

Nanostructures exhibit numerous merits to improve the efficiency in solar-to-energy conversion. These include shortened carrier collection pathways, an increased volume ratio between depletion layer and bulk, enhanced light capture due to multiple light scattering in nanostructures, and a high surface area for photochemical conversion reactions. In this study, we describe the synthesis of morphology-controlled W-doped BiVO4 by simply tuning the solvent ratio in precursor solutions. Planar and porous W-doped BiVO4 thin films were prepared and compared. The porous film, which exhibits increased surface area and enhanced light absorption, has displayed enhanced charge separation and interfacial charge injection. Our quantitative analysis showed an enhancement of about 50% of the photoelectrochemical performance for the porous structure compared to the planar structure. This enhancement is attributed to improved light absorption (13% increase), charge separation (14% increase), and interfacial charge injection (20% increase).


Sign in / Sign up

Export Citation Format

Share Document