scholarly journals Energetics of the Charge Generation in Organic Donor-Acceptor Interfaces

2021 ◽  
Author(s):  
Artur Marx Andermann ◽  
Luis G.C. Rego
Keyword(s):  
Charge Generation ◽  
Donor Acceptor

Uphill and downhill charge generation from charge transfer to charge separated states in organic solar cells

2021 ◽  
Author(s):  
Shahidul Alam ◽  
Vojtech Nádaždy ◽  
Tomáš Váry ◽  
Christian Friebe ◽  
Rico Meitzner ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Solar Cells ◽  
Charge Transfer ◽  
Energy Level ◽  
Density Of States ◽  
Organic Solar Cells ◽  
Joint Density ◽  
Charge Generation ◽  
Donor Acceptor

Energy level alignments at the organic donor–acceptor interface cannot be predicted from cyclic voltammetry. Onsets for joint density of states and charge generation, reveal cases of energy uphill and – newly observed – downhill charge generation.

scholarly journals Photoconversion Mechanism at the pn-Homojunction Interface in Single Organic Semiconductor

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1727 ◽  
Author(s):  
Ji-Hyun Lee ◽  
Armand Perrot ◽  
Masahiro Hiramoto ◽  
Seiichiro Izawa
Keyword(s):  
Organic Semiconductors ◽  
Organic Semiconductor ◽  
Energy Structure ◽  
Free Charge ◽  
Charge Generation ◽  
Recombination Processes ◽  
Single Host ◽  
Donor Acceptor ◽  
Doping Technique ◽  
Determining Factor

Clarifying critical differences in free charge generation and recombination processes between inorganic and organic semiconductors is important for developing efficient organic photoconversion devices such as solar cells (SCs) and photodetector. In this study, we analyzed the dependence of doping concentration on the photoconversion process at the organic pn-homojunction interface in a single organic semiconductor using the temperature dependence of J–V characteristics and energy structure measurements. Even though the organic pn-homojunction SC devices were fabricated using a single host material and the doping technique resembling an inorganic pn-homojunction, the charge generation and recombination mechanisms are similar to that of conventional donor/acceptor (D/A) type organic SCs; that is, the charge separation happens from localized exciton and charge transfer (CT) state being separated by the energy offset between adjacent molecules, and the recombination happens from localized charge carrier at two adjacent molecules. The determining factor for photoconversion processes is the localized nature of charges in organic semiconductors. The results demonstrated that controlling the delocalization of the charges is important to realize efficient organic photoconversion devices.

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.

Nonlinear photophysics and charge generation of donor-acceptor two-photon absorbing dyes

2003 ◽  
Author(s):  
Sean M. Kirkpatrick ◽  
Elaine K. Peterman ◽  
Gregg T. Anderson ◽  
Jeffrey E. Franklin ◽  
Jeffery W. Baur
Keyword(s):  
Charge Generation ◽  
Two Photon ◽  
Donor Acceptor

scholarly journals Appropriate Donor-Acceptor Phase Separation Structure for the Enhancement of Charge Generation and Transport in Polymer Solar Cells

Polymers ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 332 ◽  
Author(s):  
Dayong Zhang ◽  
Rong Hu ◽  
Jiang Cheng ◽  
Yuqiang Chang ◽  
Mingming Huo ◽  
...  
Keyword(s):  
Solar Cells ◽  
Phase Separation ◽  
Polymer Solar Cells ◽  
Charge Generation ◽  
Donor Acceptor ◽  
Acceptor Phase

scholarly journals Efficient Charge Generation Via Hole Transfer in Dilute Organic Donor-Fullerene Blends

2019 ◽  
Author(s):  
Yin Song ◽  
Alexander Schubert ◽  
Xiao Liu ◽  
Srijana Bhandari ◽  
Stephen R. Forrest ◽  
...  
Keyword(s):  
Density Functional ◽  
Electronic Spectroscopy ◽  
Golden Rule ◽  
Charge Generation ◽  
Functional Theory ◽  
Hole Transfer ◽  
Electronic Interactions ◽  
Efficient Charge ◽  
Donor Acceptor ◽  
Via Hole

<p>Efficient organic photovoltaics (OPVs) require broadband charge photogeneration with near-unity quantum yield. This can only be achieved by exploiting all pathways that generate charge. Electron transfer from organic donors to acceptors has been well-studied and is considered the primary path to charge photogeneration in OPVs. In contrast, much less is known about the hole transfer pathway. </p><p>Here we study charge photogeneration in an archetypical system comprising tetraphenyldibenzoperiflanthene: C70 blends using our recently developed multispectral two dimensional electronic spectroscopy (M-2DES), supported by time-dependent density functional theory and fully quantum-mechanical Fermi’s golden rule rate calculations. Our approach identifies in real time two rapid charge transfer pathways that are confirmed through computational analysis. Surprisingly, we find that both electron and hole transfer occur with comparable rates and efficiencies, facilitated by donor-acceptor electronic interactions. Our results highlight the importance of the hole transfer pathway for optimizing the efficiency of OPV devices employing small-molecule heterojunctions.<br></p>

Charge Generation in Non-Fullerene Donor–Acceptor Blends for Organic Solar Cells

2017 ◽  
Vol 121 (34) ◽  
pp. 18412-18422 ◽  
Author(s):  
Nasim Zarrabi ◽  
Dani M. Stoltzfus ◽  
Paul L. Burn ◽  
Paul E. Shaw
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Charge Generation ◽  
Donor Acceptor

Impact of Bridging Units on the Dynamics of Photoinduced Charge Generation and Charge Recombination in Donor–Acceptor Dyads

ChemPhysChem ◽  
2007 ◽  
Vol 8 (8) ◽  
pp. 1240-1249 ◽  
Author(s):  
Antoine Van Vooren ◽  
Vincent Lemaur ◽  
Aijun Ye ◽  
David Beljonne ◽  
Jérôme Cornil
Keyword(s):  
Charge Recombination ◽  
Charge Generation ◽  
Donor Acceptor ◽  
Photoinduced Charge

Steric Control of the Donor/Acceptor Interface: Implications in Organic Photovoltaic Charge Generation

2011 ◽  
Vol 133 (31) ◽  
pp. 12106-12114 ◽  
Author(s):  
Thomas W. Holcombe ◽  
Joseph E. Norton ◽  
Jonathan Rivnay ◽  
Claire H. Woo ◽  
Ludwig Goris ◽  
...  
Keyword(s):  
Organic Photovoltaic ◽  
Charge Generation ◽  
Donor Acceptor ◽  
Steric Control
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