Imaging of Photoinduced Interfacial Charge Separation in Conjugated Polymer/Semiconductor Nanocomposites

2009 ◽  
Vol 113 (21) ◽  
pp. 9368-9374 ◽  
Author(s):  
Ruchuan Liu
Keyword(s):  
Charge Separation ◽  
Conjugated Polymer ◽  
Polymer Semiconductor ◽  
Semiconductor Nanocomposites ◽  
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 A high-spin ground-state donor-acceptor conjugated polymer

2019 ◽  
Vol 5 (5) ◽  
pp. eaav2336 ◽  
Author(s):  
A. E. London ◽  
H. Chen ◽  
M. A. Sabuj ◽  
J. Tropp ◽  
M. Saghayezhian ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
High Spin ◽  
Ground State ◽  
Conjugated Polymer ◽  
Organic Materials ◽  
Energy Gap ◽  
Light Element ◽  
Paramagnetic Resonance ◽  
Practical Applications ◽  
Polymer Semiconductor

Interest in high-spin organic materials is driven by opportunities to enable far-reaching fundamental science and develop technologies that integrate light element spin, magnetic, and quantum functionalities. Although extensively studied, the intrinsic instability of these materials complicates synthesis and precludes an understanding of how fundamental properties associated with the nature of the chemical bond and electron pairing in organic materials systems manifest in practical applications. Here, we demonstrate a conjugated polymer semiconductor, based on alternating cyclopentadithiophene and thiadiazoloquinoxaline units, that is a ground-state triplet in its neutral form. Electron paramagnetic resonance and magnetic susceptibility measurements are consistent with a high-to-low spin energy gap of 9.30 × 10−3 kcal mol−1. The strongly correlated electronic structure, very narrow bandgap, intramolecular ferromagnetic coupling, high electrical conductivity, solution processability, and robust stability open access to a broad variety of technologically relevant applications once thought of as beyond the current scope of organic semiconductors.

scholarly journals Charge transport in conjugated polymer–semiconductor nanoparticle composite near the percolation threshold

2017 ◽  
Vol 123 (12) ◽  
Author(s):  
L. S. Cardoso ◽  
G. E. Gonçalves ◽  
D. H. F. Kanda ◽  
R. F. Bianchi ◽  
H. N. Nagashima
Keyword(s):  
Charge Transport ◽  
Percolation Threshold ◽  
Conjugated Polymer ◽  
Semiconductor Nanoparticle ◽  
Polymer Semiconductor

A pseudo-two-dimensional conjugated polysquaraine: an efficient p-type polymer semiconductor for organic photovoltaics and perovskite solar cells

2018 ◽  
Vol 6 (28) ◽  
pp. 13644-13651 ◽  
Author(s):  
Qi Xiao ◽  
Fei Wu ◽  
MengMeng Han ◽  
Zhen Li ◽  
LinNa Zhu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Conjugated Polymer ◽  
Polymer Solar Cells ◽  
Perovskite Solar Cells ◽  
Two Dimensional ◽  
Free Hole ◽  
Polymer Semiconductor ◽  
Hole Transporting ◽  
Hole Transporting Material ◽  
P Type

A new squaraine-based 2D conjugated polymer was developed as the donor material in polymer solar cells and dopant-free hole transporting material in inverted perovskite solar cells, reaching efficiencies of 6.35% and 18.29%, respectively.

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.

An Efficient Strategy for Boosting Photogenerated Charge Separation by Using Porphyrins as Interfacial Charge Mediators

2019 ◽  
Vol 131 (47) ◽  
pp. 16956-16961 ◽  
Author(s):  
Xingming Ning ◽  
Bingzhang Lu ◽  
Zhen Zhang ◽  
Peiyao Du ◽  
Hongxia Ren ◽  
...  
Keyword(s):  
Charge Separation ◽  
Efficient Strategy ◽  
Photogenerated Charge Separation ◽  
Interfacial Charge
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