Frontispiece: Extending Long-lived Charge Separation Between Donor and Acceptor Blocks in Novel Copolymer Architectures Featuring a Sensitizer Core

Organic solar cells (OSCs) are discussed at length in terms of its performance leading to the generation of electricity. The key materials required for OSCs are the small organic molecules having donor and acceptor with suitable light absorption and electro-chemical properties of low energy band gap. Various structural scaffolds are highlighted with their structural design leading to film forming in an orderly manner and this morphology of film having a pivotal role in photo-induced charge separation, migration and collection at an electrode. Present day research informs that OSCs involving non fullerene based donors and acceptors are functioning with high photo conversion efficiency [PCE] of >17% and are promising candidates for practical applications.

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Ultrafast charge separation and exciplex formation induced by strong interaction between electron donor and acceptor at short distances

The Journal of Chemical Physics ◽

10.1063/1.481326 ◽

2000 ◽

Vol 112 (16) ◽

pp. 7111-7117 ◽

Cited By ~ 24

Author(s):

Shinichiro Iwai ◽

Shigeo Murata ◽

Ryuzi Katoh ◽

M. Tachiya ◽

Koichi Kikuchi ◽

...

Keyword(s):

Electron Donor ◽

Strong Interaction ◽

Charge Separation ◽

Exciplex Formation ◽

Donor And Acceptor ◽

Electron Donor And Acceptor

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Nanometer-Scaled Landscape of Polymer:Fullerene Blends Mapped with Visible s-SNOM

Nanotechnology ◽

10.1088/1361-6528/ac46b5 ◽

2021 ◽

Author(s):

Ya-Rong Lee ◽

Cheng-Chia Huang ◽

Wen-Yu Huang ◽

Chin-Ti Chen ◽

Ping-Tsung Huang ◽

...

Keyword(s):

Active Layer ◽

Organic Solar Cells ◽

Charge Separation ◽

High Performance ◽

Bulk Heterojunction ◽

Near Field ◽

Photovoltaic Performance ◽

Energy Landscapes ◽

Donor And Acceptor ◽

Shed Light

Abstract Bulk heterojunction is one key concept leading to breakthrough in organic photovoltaics. The active layer is expectantly formed of distinct morphologies that carry out their respective roles in photovoltaic performance. The morphology-performance relationship however remains stymied, because unequivocal morphology at the nanoscale is not available. We used scattering-type scanning near-field optical microscopy operating with a visible light source (visible s-SNOM) to disclose the nanomorphology of P3HT:PCBM and pBCN:PCBM blends. Donor and acceptor domain as well as intermixed phase were identified and their intertwined distributions were mapped. We proposed energy landscapes of the BHJ active layer to shed light on the roles played by these morphologies in charge separation, transport and recombination. This study shows that visible s-SNOM is capable of profiling the morphological backdrop pertaining to the operation of high performance organic solar cells.

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Transient states in photoinduced electron transfer reactions of porphyrin- and phthalocyanine-fullerene dyads

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s108842460900139x ◽

2009 ◽

Vol 13 (10) ◽

pp. 1090-1097 ◽

Cited By ~ 13

Author(s):

Helge Lemmetyinen ◽

Nikolai Tkachenko ◽

Alexander Efimov ◽

Marja Niemi

Keyword(s):

Electron Transfer ◽

Charge Separation ◽

Photoinduced Electron Transfer ◽

Transient State ◽

Primary Electron ◽

Transfer Reactions ◽

Acceptor Pair ◽

Electron Transfer Reactions ◽

Exciplex Formation ◽

Donor And Acceptor

This paper combines the most important results on studies performed by the authors during the last decade on photoinduced electron transfer reactions of pheophytin-, phthalocyanine-, and porphyrin-fullerene dyads, in which donor and acceptor moieties are covalently linked to each other. Practically all studied molecules form an intramolecular exciplex as a transient state before the formation of the charge separation state or tight ion pair. When the center-to-center distance of the donor and acceptor pair is short (7–10 Å) both the exciplex formation and primary electron transfer are extremely fast with rate constants of 7–23 × 1012 s -1 and 40–1400 × 109 s -1, respectively. Rates become slower when the distance and orientational fluctuation increases. No systematic correlation between free energies and the rates of the formation and recombination of the exciplex and the charge separation state, respectively, were observed. The mechanism is discussed in frames of the Marcus electron transfer and the radiationless quantum transition theories.

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Theoretical study on mesoscopic-size impurity effects in the charge separation process of organic photocells

Physical Chemistry Chemical Physics ◽

10.1039/c7cp08125a ◽

2018 ◽

Vol 20 (21) ◽

pp. 14846-14854

Author(s):

Tomomi Shimazaki ◽

Motomichi Tashiro ◽

Takahito Nakajima

Keyword(s):

Charge Separation ◽

High Performance ◽

Theoretical Study ◽

Bulk Heterojunction ◽

Separation Process ◽

Impurity Effects ◽

Heterojunction Structure ◽

Donor And Acceptor

A bulk-heterojunction structure is often employed to develop high-performance organic photocells, in which the donor and acceptor regions are complexly intertwined.

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Construction of Segregated Arrays of Multiple Donor and Acceptor Units Using a Dendritic Scaffold: Remarkable Dendrimer Effects on Photoinduced Charge Separation

Journal of the American Chemical Society ◽

10.1021/ja063081t ◽

2006 ◽

Vol 128 (32) ◽

pp. 10527-10532 ◽

Cited By ~ 86

Author(s):

Wei-Shi Li ◽

Kil Suk Kim ◽

Dong-Lin Jiang ◽

Hiroyuki Tanaka ◽

Tomoji Kawai ◽

...

Keyword(s):

Charge Separation ◽

Donor And Acceptor ◽

Photoinduced Charge Separation ◽

Photoinduced Charge

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Effects of end-on oriented polymer chains at the donor/acceptor interface in organic solar cells

Journal of Materials Chemistry A ◽

10.1039/c8ta09307e ◽

2018 ◽

Vol 6 (45) ◽

pp. 22889-22898 ◽

Cited By ~ 11

Author(s):

Fanji Wang ◽

Kyohei Nakano ◽

Hiroyuki Yoshida ◽

Kazuhito Hashimoto ◽

Hiroshi Segawa ◽

...

Keyword(s):

Solar Cells ◽

Organic Solar Cells ◽

Charge Separation ◽

Polymer Chains ◽

Oriented Polymer ◽

Coulombic Interaction ◽

Donor And Acceptor ◽

Donor Acceptor

Intrachain hole delocalization vertical to donor and acceptor interface weakens coulombic interaction of the charge pairs and facilitate the charge separation in organic solar cells.

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Synthesis and photochemical studies of a tris(4-iodophenoxy) subphthalocyaninato boron(III)-fulleropyrrolidine dyad

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424615500947 ◽

2016 ◽

Vol 20 (08n11) ◽

pp. 987-996 ◽

Cited By ~ 3

Author(s):

Robert Cantu ◽

Habtom B. Gobeze ◽

Francis D’Souza

Keyword(s):

Charge Separation ◽

Transient Absorption ◽

Cycloaddition Reaction ◽

Differential Pulse ◽

Redox Potentials ◽

Fluorescence Studies ◽

Optical Absorbance ◽

Femtosecond Transient Absorption ◽

Donor And Acceptor ◽

Absorption Studies

A subphthalocyanine-fullerene dyad, 1 was newly synthesized through axial functionalization via central boron of subphthalocyanine with [Formula: see text]-hydroxybenzaldehyde, and subsequent dipolar cycloaddition reaction of fullerene. The subphthalocyanine entity was peripherally functionalized with moderately electron rich 4-iodophenoxy substituents to probe their effect on photoinduced processes within the SubPc-C[Formula: see text] dyad. Optical absorbance studies revealed presence of both entities of the dyad while steady-state fluorescence studies revealed quenching of subphthalocyanine emission in the dyad in both nonpolar toluene and polar benzonitrile solvents. Further, redox potentials of the donor and acceptor entities were obtained by differential pulse voltammetry, and energy of different photochemical processes was evaluated. Femtosecond transient absorption studies revealed occurrence of charge separation in the SubPc-C[Formula: see text] dyad either from the 1SubPc* or 1C[Formula: see text]* in both nonpolar and polar solvents. That is, transient peaks in the 665 nm range corresponding to SubPc[Formula: see text] and at 1015 nm corresponding to C[Formula: see text] was possible to spectrally identify. The measured rate of charge separation, [Formula: see text] was found to be ∼7.0 × 10[Formula: see text] s[Formula: see text] irrespective of the solvent. The rate of charge recombination, [Formula: see text] from the decay of the C[Formula: see text] peak was found to be 1.1 × 109 s[Formula: see text] in toluene and 1.3 × 109 s[Formula: see text] in benzonitrile, respectively. The SubPc[Formula: see text]-C[Formula: see text] radical ion-pair populated the low-laying 3SubPc* prior returning to the ground state.

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