See all authors In organic solar cells with very small energetic-offset (ΔE LE − CT), the charge-transfer (CT) and local-exciton (LE) states strongly interact via electronic hybridization and thermal population effects, suppressing the non-radiative recombination.
Instead, they assume that each exciton generated in the bulk dissociates into a CT state via charge transfer at a rate independent of exciton diffusion. In this work, the role of exciton diffusion in exciton dissociation and charge generation yield of low-offset organic solar cells is investigated.
For the process of photovoltaic conversion in organic solar cells (OSCs) and quantum-dot solar cells (QDSCs), three of four steps are determined by exciton behavior, namely, exciton generation, exciton diffusion, and exciton dissociation.
Recent developments in computational methodologies make it possible to capture the effects of solid-state electronic polarization on gap renormalizations (that is, stabilization of the hole and electron transport levels) and screening of the electrostatic electron–hole interactions.
The enhanced LD for superior exciton diffusion and dissociation boosts PM6:L8-BO-F:BTP-eC9 ternary solar cells having a layer-by-layer structure to achieve higher PCEs of 18.53% with a film thickness of 120 nm and 15.21% with a film thickness of 500 nm.
Fig. 1: Charge-carrier formation in organic solar cells. Electronic-state diagram illustrating the processes involved in photoinduced charge-carrier formation in an organic solar cell. LE is the lowest-energy local-exciton singlet or triplet excited state (mainly localized on either the electron-donor (D) or electron-acceptor (A) component).
An Insight into the Excitation States of Small Molecular ...
Y6 is a new type of non-fullerene acceptor, which has led to power conversion efficiencies of single-junction polymer solar cells over 17% when combined with a careful choice of polymeric donors. However, the excited state characteristics of Y6, which is closely correlated with its opto-electronic applications, are not clear yet. In ...
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The nature of excited states in dipolar donor/fullerene …
Electronic delocalization at donor/acceptor (D/A) interfaces can play an important role in photocurrent generation for organic solar cells. Here, we have investigated the nature of local excited and interfacial charge transfer …
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Revealing the Excited-State Dynamics in a Dye-Sensitized Solar Cell ...
Chlorophylls (Chls) used as the sensitizers in the fabrication of natural dye-sensitized solar cells (NDSSCs) are usually extracted directly using a soaking method. Consequently, they are actually multipigment mixtures. In this study, the Chl mixture-based NDSSC exhibited a low photoconversion efficiency of ∼0.09% and a fill-factor ...
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Exciton diffusion and dissociation in organic and quantum‐dot solar cells
For the process of photovoltaic conversion in organic solar cells (OSCs) and quantum-dot solar cells (QDSCs), three of four steps are determined by exciton behavior, namely, exciton generation, exciton diffusion, and exciton dissociation.
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Exciton diffusion and dissociation in organic and …
For the process of photovoltaic conversion in organic solar cells (OSCs) and quantum-dot solar cells (QDSCs), three of four steps are determined by exciton behavior, namely, exciton generation, exciton diffusion, and exciton …
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Correlating excited state and charge carrier dynamics with …
Two perylene dyes characteristic of electron-donors phenanthrocarbazole (PC) and carbazyl functionalized PC are selected to study the complicated dynamics of excited states and charge carriers, which underlie the photovoltaic parameters of dye-sensitized solar cells (DSCs). We have combined femtosecond fluor
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Long-lived and disorder-free charge transfer states enable ...
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 ...
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Temperature-dependent excited states for detecting …
Temperature-dependent excited states for detecting reversible phase transitions in 2D lead ... phase transitions but also would help to understand their excited states in more details to selectively use them for solar …
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Engineering Charge-Transfer States for Efficient, Low-Energy …
Charge transfer (CT) between donors and acceptors following photoexcitation of organic photovoltaics (OPVs) gives rise to bound electron–hole pairs across the donor–acceptor interface, known as CT states. While these states are essential to charge separation, they are also a source of energy loss.
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Revealing the Excited-State Dynamics in a Dye-Sensitized Solar …
Chlorophylls (Chls) used as the sensitizers in the fabrication of natural dye-sensitized solar cells (NDSSCs) are usually extracted directly using a soaking method. …
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Assessing the nature of the charge-transfer electronic states in ...
The charge-transfer electronic states appearing at the donor-acceptor interfaces in organic solar cells mediate exciton dissociation, charge generation, and charge recombination. To date, the ...
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Efficient organic macrocyclic photosensitizers and hole …
We have examined their light absorbing ability, fluorescence emission efficiency, fluorescence lifetime length, excited triplet state formation properties, singlet oxygen production yield, and the application as hole transporting materials in metal halide perovskite solar cells. The techniques used are UV–Vis electronic absorption, steady state and time resolved UV–Vis and …
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Role of Exciton Diffusion and Lifetime in Organic Solar Cells with a ...
Despite general agreement that the generation of free charges in organic solar cells is driven by an energetic offset, power conversion efficiencies have been improved using low-offset blends. In this work, we explore the interconnected roles that exciton diffusion and lifetime play in the charge generation process under various energetic offsets.
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The nature of excited states in dipolar donor/fullerene complexes …
Electronic delocalization at donor/acceptor (D/A) interfaces can play an important role in photocurrent generation for organic solar cells. Here, we have investigated the nature of local excited and interfacial charge transfer (CT) states in model complexes including one to four anti-parallel stacking dipola
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[PDF] Impact of Triplet Excited States on the Open‐Circuit …
The best organic solar cells (OSCs) achieve comparable peak external quantum efficiencies and fill factors as conventional photovoltaic devices. However, their voltage losses are much higher, in particular those due to nonradiative recombination. To investigate the possible role of triplet states on the donor or acceptor materials in this process, model systems …
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Engineering Charge-Transfer States for Efficient, Low-Energy-Loss ...
Charge transfer (CT) between donors and acceptors following photoexcitation of organic photovoltaics (OPVs) gives rise to bound electron–hole pairs across the …
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Role of Exciton Diffusion and Lifetime in Organic Solar …
Despite general agreement that the generation of free charges in organic solar cells is driven by an energetic offset, power conversion efficiencies have been improved using low-offset blends. In this work, we …
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Triplet Excitons and Associated Efficiency‐Limiting Pathways in …
1 Introduction. Organic solar cells (OSC) based on non-fullerene acceptors (NFAs) have attracted much attention due to their strong absorption in the visible and near infrared spectral regions and their energy-level tunability, in contrast to fullerene acceptors. [] However, despite the great success of OSC development to power conversion efficiencies …
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Correlating the Hybridization of Local‐Exciton and Charge‐Transfer ...
In organic solar cells with very small energetic-offset (ΔE LE − CT), the charge-transfer (CT) and local-exciton (LE) states strongly interact via electronic hybridization and thermal population effects, suppressing the non-radiative recombination. Here, we investigated the impact of these effects on charge generation and ...
Learn More
An Insight into the Excitation States of Small Molecular …
Y6 is a new type of non-fullerene acceptor, which has led to power conversion efficiencies of single-junction polymer solar cells over 17% when combined with a careful choice of polymeric donors. However, the …
Learn More
