Phosphorescence and delayed fluorescence of poly(3-hexylthiophene) films

Holdcroft, Steven

doi:10.1016/0040-6090(94)90524-x

Cited by 16 publications

(16 citation statements)

References 29 publications

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“…A similar trend is observed by Gonzales et al for doped P3HT:PCBM solar cells [24]. The results for exciton diffusion lengths and lifetime conform with the experimental values within ideal material setups, documented in [63,64,86,99]. Similar to the trend observed in [24,26], the lifetime of excitons decreases with dopant concentration.…”

Section: Impact Of Dopant Volume Concentration On Exciton Dynamicssupporting

confidence: 76%

“…The BHJ reduces the distance between the generation position of an exciton and the donor-acceptor interface. This distance should be as short as possible, as singlets have short diffusion lengths of 3-6 nm [63]. If the distance between origin and interface exceeds the diffusion length, singlet excitons probably decay before reaching an interface and cannot be converted into usable electrical energy.…”

Section: Phosphorescent Dopantsmentioning

confidence: 99%

“…Triplet excitons exhibit an effective lifetime of 10 µs for P3HT, which corresponds to a diffusion length of 100 nm [63]. The spin selection rules forbid the radiative decay of triplet excitons.…”

Section: Phosphorescent Dopantsmentioning

confidence: 99%

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Generalized Kinetic Monte Carlo Framework for Organic Electronics

et al. 2018

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Abstract:In this paper, we present our generalized kinetic Monte Carlo (kMC) framework for the simulation of organic semiconductors and electronic devices such as solar cells (OSCs) and light-emitting diodes (OLEDs). Our model generalizes the geometrical representation of the multifaceted properties of the organic material by the use of a non-cubic, generalized Voronoi tessellation and a model that connects sites to polymer chains. Herewith, we obtain a realistic model for both amorphous and crystalline domains of small molecules and polymers. Furthermore, we generalize the excitonic processes and include triplet exciton dynamics, which allows an enhanced investigation of OSCs and OLEDs. We outline the developed methods of our generalized kMC framework and give two exemplary studies of electrical and optical properties inside an organic semiconductor.

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Section: Impact Of Dopant Volume Concentration On Exciton Dynamicssupporting

confidence: 76%

Section: Phosphorescent Dopantsmentioning

confidence: 99%

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Generalized Kinetic Monte Carlo Framework for Organic Electronics

et al. 2018

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“…Using eq. [3], the quantum yield of cross-linking, @, , at 435 nm was calculated to be 2.37 x moueinstein-'. Using the ratio pol q,, the quantum yield of main-chain scission, Q, , was estimated to be 5.45 x moueinstein.…”

Section: Resultsmentioning

confidence: 99%

“…The effect of light on T-conjugated polymers plays an important role when they are utilized in specialized technical innovations such as optoelectronic devices, photoconduction (I), electroluminescence (2,3), photovoltaics (4), and photolithography of semiconducting and electronically conducting polymer wires in the design of integrated circuitry and device fabrication (5)(6)(7)(8). However, few studies probe the chemical reactions that result from the interaction of light with T-conjugated polymers.…”

Section: Introduction Effect Of Light On These Materials and To Impromentioning

confidence: 99%

Solid-state photochemistry of π-conjugated poly(3-alkylthiophenes)

Abdou¹,

Holdcroft²

1995

Can. J. Chem.

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Films of poly(3-alkylthiophenes) undergo simultaneous photobleaching, cross-linking, and chain scission when irradiated in air with UV or visible light. The quantum yields of the latter two processes were determined using Chalesby-Pinner theory. Under the irradiation conditions employed the cross-linking density is -4.5 times greater than the fracture density (chain scission). This corroborates the observation that poly(3-alkylthiophenes) are negative-type photoresists. Although the quantum yield of cross-linking is relatively low, the polymer maintains a relatively high degree of IT-conjugation following irradiation. The mechanism of crosslinking and insolubilization proceeds via a classical photooxidation route that is initiated by photolysis of residual iron impurities. Photobleaching involves photosensitization, and reaction of singlet oxygen. '0, undergoes a 1,4 Diels-Alder addition to thienyl units which results in a loss of IT-conjugation, a blue shift in the absorption spectrum of the polymer, and a decrease in the optical density. Photobleaching, cross-linking, and chain scission are considerably reduced in the absence of oxygen.Key words: photochemistry, polymers, thin films, degradation, cross-linking.RCsumC : Lorsqu'on les soumet B une irradiation UV ou visible dans l'air, les films de poly(3-alkylthiophbnes) subissent des photoblanchiments, des rtticulations et des scissions de chaines simultants. Utilisant la thCorie de Chalesby-Pinner, on a determink les rendements quantiques des deux derniers processus. Dans les conditions d'irradiation employtes, la densitk de la rkticulation est environ 4,5 fois plus grande que la densitk de fracture (scission des chaines). Ces rksultats corroborent l'observation que les poly (3-alkylthiophbnes) sont des photorksistances de type nkgatif. M&me si le rendement quantique de la rkticulation est relativement bas, le polymbre maintient un degrk relativernent klevk de conjugaison IT aprbs l'irradiation. Le mkcanisme de rkticulation et d'insolubilisation procbde par le biais d'une photooxydation classique qui est initike par la photolyse d'impuretks ferriques rksiduelles. Le photoblanchiment irnplique une photosensibilitation et la reaction d'un oxygbne singulet. Le '0, subit une addition-1,4 de Diels-Alder sur les unites thiknyles qui provoquent une perte de conjugaison IT, un dkplacement vers le bleu dans le spectre d'absorption du polymbre et une diminution de la densitk optique. Les rkactions de photoblanchiment, rkticulation et scission de chaine sont forternent rtduites en l'absence d'oxygbne.

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Impact of Phosphorescent Sensitizers and Morphology on the Photovoltaic Performance in Organic Solar Cells

Popp

Kaiser

Gagliardi

2018

Advcd Theory and Sims

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Phosphorescent sensitizers (PSs) are considered as a promising alternative for increasing the internal quantum efficiency (IQE) in organic solar cells (OSCs). By converting short-lifetime singlet into long-living triplet excitons, enhanced exciton diffusion and dissociation have been reported previously. However, only a limited increase in the OSC performance has been achieved. In this work, the interplay of the PS with both singlet and triplet excitons within organic blends is examined using kinetic Monte Carlo simulations including a comprehensive model of excitonic processes. Different morphologies of the conventional P3HT:PCBM solar cell are simulated, and the excitonic properties and their influence on the photovoltaic performance under doping are studied. The use of phosphorescent sensitization ensures high intersystem crossing and enlarges the diffusion length. An increase in the IQE of 34% is observed for a bilayer OSC. The increasing decay of triplets in proximity to the PS due to a strong spin-orbit coupling limits the IQE. Unlike expected, triplet-triplet annihilation does not provide a significant loss of excitons. A doped planar-mixed molecular heterojunction outperforms an undoped bulk-heterojunction OSC due to the enhanced exciton diffusion. A further study of optimal PS parameters predicts an increase in the IQE within bilayer solar cells by about 100%.

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Phosphorescence and delayed fluorescence of poly(3-hexylthiophene) films

Cited by 16 publications

References 29 publications

Generalized Kinetic Monte Carlo Framework for Organic Electronics

Generalized Kinetic Monte Carlo Framework for Organic Electronics

Solid-state photochemistry of π-conjugated poly(3-alkylthiophenes)

Impact of Phosphorescent Sensitizers and Morphology on the Photovoltaic Performance in Organic Solar Cells

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