Determining the optimum morphology in high-performance polymer-fullerene organic photovoltaic cells

Hedley, Gordon J.; Ward, Alexander J.; Алексеев, А. В.; Howells, Calvyn Travis; Martins, Emiliano R.; Serrano, Luis A.; Cooke, Graeme; Ruseckas, Arvydas; Samuel, Ifor D. W.

doi:10.1038/ncomms3867

Cited by 321 publications

(417 citation statements)

References 56 publications

(87 reference statements)

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“…We use the known diffusion length of PCBM excitons of 3.2 -5 nm, determined experimentally with time-resolved laser spectroscopic techniques. 41,42 Using this analysis,…”

Section: Morphology Of Siidt-dtbt:pc70bm Blendsmentioning

confidence: 99%

Charge Separation in Intermixed Polymer:PC₇₀BM Photovoltaic Blends: Correlating Structural and Photophysical Length Scales as a Function of Blend Composition

et al. 2017

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A key challenge in achieving control over photocurrent generation by bulk-heterojunction organic solar cells is understanding how the morphology of the active layer impacts charge separation and in particular the separation dynamics within molecularly-intermixed donor-acceptor domains versus the dynamics between phase-segregated domains. This paper addresses this issue by studying blends and devices of the amorphous silicon-indacenodithiophene polymer SiIDT-DTBT and the acceptor PC70BM. By changing the blend composition, we modulate the size and density of the pure and intermixed domains on the nanometre lengthscale. Laser spectroscopic studies show that these changes in morphology correlate quantitatively with the changes in charge separation dynamics on the 2 nanosecond timescale, and with device photocurrent densities. At low fullerene compositions, where only a single, molecularly intermixed polymer-fullerene phase is observed, photoexcitation results in a ~30% charge loss from geminate polaron pair recombination, which is further studied via light intensity experiments showing that the radius of the polaron pairs in the intermixed phase is 3-5 nm. At high fullerene compositions (≥ 67%), where the intermixed domains are 1-3 nm and the pure fullerene phases reach ~4 nm, the geminate recombination is suppressed by the reduction of the intermixed phase making the fullerene domains accessible for electron escape.

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“…We use the known diffusion length of PCBM excitons of 3.2 -5 nm, determined experimentally with time-resolved laser spectroscopic techniques. 41,42 Using this analysis,…”

Section: Morphology Of Siidt-dtbt:pc70bm Blendsmentioning

confidence: 99%

Charge Separation in Intermixed Polymer:PC₇₀BM Photovoltaic Blends: Correlating Structural and Photophysical Length Scales as a Function of Blend Composition

et al. 2017

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“…By integrating the area under the carbon 1s and sulfur 2p spectra (peak at 163.4 eV) and normalizing to their relative sensitivity factors, we notice that the S:C ratio increases from 0.08:0.92 to 0.10:0.9 after ASSQ and DPSQ were mixed in the polymer:fullerene matrix. Because only the polymer contains sulfur element, this indicates that the squaraines promote a more polymer-rich surface formation, resulting in a better concentration gradient for charge extraction near the cathode interface [8,9] for inverted solar cells. We attempted to quantify the percentage of squaraines on the surface by repetitively scanning the region from 395 to 408 eV binding energy, but the signal from the nitrogen 1s is not discernable ( Supplementary Information, S5b) in 2% ASSQ-DPSQ PTB7:PC 71 BM film.…”

Section: S3fmentioning

confidence: 99%

Quaternary Organic Solar Cells Enhanced by Cocrystalline Squaraines with Power Conversion Efficiencies >10%

Goh

Huang

Yager

et al. 2016

Advanced Energy Materials

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The incorporation of multiple donors into the bulk‐heterojunction layer of organic polymer solar cells (PSCs) has been demonstrated as a practical and elegant strategy to improve photovoltaics performance. However, it is challenging to successfully design and blend multiple donors, while minimizing unfavorable interactions (e.g., morphological traps, recombination centers, etc.). Here, a new Förster resonance energy transfer‐based design is shown utilizing the synergistic nature of three light active donors (two small molecules and a high‐performance donor–acceptor polymer) with a fullerene acceptor to create highly efficient quaternary PSCs with power conversion efficiencies (PCEs) of up to 10.7%. Within this quaternary architecture, it is revealed that the addition of small molecules in low concentrations broadens the absorption bandwidth, induces cocrystalline molecular conformations, and promotes rapid (picosecond) energy transfer processes. These results provide guidance for the design of multiple‐donor systems using simple processing techniques to realize single‐junction PSC designs with unprecedented PCEs.

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“…In this work we use state-of-the-art organic solar cells based on PTB7:PC71BM material blends ( Fig. 1(a)) [14][15][16] to achieve high power conversion efficiency. We show that data rates of over 34 Mbps are possible while the solar cell maintains its full power generation capabilities.…”

mentioning

confidence: 99%

Organic solar cells as high-speed data detectors for visible light communication

Zhang¹,

Tsonev²,

Videv³

et al. 2015

Optica

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We show that solar cells, widely used in portable devices for power generation, can simultaneously extract a highspeed data signal in an optical wireless communication link. This paper reports the first use of an organic solar cell as an energy-harvesting receiver for visible light communications (VLC). While generating maximum power in the cell, the communication link can deliver a data-rate of 34.2 Mbps with a bit error rate of 4.08 × 10 -4 using an implementation of orthogonal frequency division multiplexing. This approach could lead to printed optical data receivers in future eco-friendly VLC systems. The looming radio frequency (RF) spectrum crunch has prompted research into alternative regions of the electromagnetic (EM) spectrum for future wireless communication systems. The infrared and visible light region of the EM spectrum are of particular interest since the vast amount of available bandwidth is unregulated and free of electromagnetic interference (EMI). The growing infrastructure of LED lighting offers a particular opportunity for visible light communications (VLC) with power-efficient dual-use sources, which provide simultaneous illumination and very high rate wireless data transmission [1][2][3][4][5]. While VLC data links normally use photodiode (PD) receivers [5] (either positive-intrinsic-negative (PIN) PDs or avalanche PDs), there is a parallel opportunity for duality by using instead a solar cell for simultaneous energy harvesting and data detection. Wang et al. recently showed that a standard commercial multi-crystalline silicon solar panel could be used for this dual purpose, to receive a data-rate of 11.84 Mbps while generating approximately 2 mW of electrical power [6,7]. This advance implies that it could be possible for any piece of electronic equipment with an integrated solar cell to engage in highspeed data communication while utilising the energy from the light signal or ambient lighting to power the receiver electronics.However, to unlock the full potential of this approach it would be very attractive to use an alternative solar cell technology that could be more easily integrated on different devices/substrates, or even be mechanically flexible. The field of organic electronics offers these possibilities, and here we report the first use of an organic semiconductor solar cell as the energy-harvesting receiver in an optical wireless data link. When the cell generates maximum power, the communication link is capable of delivering a data-rate of 34.2 Mbps with a bit error rate (BER) of 4.08 × 10 -4 using an implementation of orthogonal frequency division multiplexing (OFDM). Such organic solar cells could serve as a future platform for ubiquitous VLC receivers. They can be mass manufactured by roll-to-roll printing on a flexible foil [8], giving the possibility of very inexpensive flexible/conformal panels which could be integrated with an extremely wide range of devices. They offer relatively easy bandgap tuning through the visible which could allow a selective response to wavelengt...

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Determining the optimum morphology in high-performance polymer-fullerene organic photovoltaic cells

Cited by 321 publications

References 56 publications

Charge Separation in Intermixed Polymer:PC₇₀BM Photovoltaic Blends: Correlating Structural and Photophysical Length Scales as a Function of Blend Composition

Charge Separation in Intermixed Polymer:PC₇₀BM Photovoltaic Blends: Correlating Structural and Photophysical Length Scales as a Function of Blend Composition

Quaternary Organic Solar Cells Enhanced by Cocrystalline Squaraines with Power Conversion Efficiencies >10%

Organic solar cells as high-speed data detectors for visible light communication

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Determining the optimum morphology in high-performance polymer-fullerene organic photovoltaic cells

Cited by 321 publications

References 56 publications

Charge Separation in Intermixed Polymer:PC70BM Photovoltaic Blends: Correlating Structural and Photophysical Length Scales as a Function of Blend Composition

Charge Separation in Intermixed Polymer:PC70BM Photovoltaic Blends: Correlating Structural and Photophysical Length Scales as a Function of Blend Composition

Quaternary Organic Solar Cells Enhanced by Cocrystalline Squaraines with Power Conversion Efficiencies >10%

Organic solar cells as high-speed data detectors for visible light communication

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Product

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Charge Separation in Intermixed Polymer:PC₇₀BM Photovoltaic Blends: Correlating Structural and Photophysical Length Scales as a Function of Blend Composition

Charge Separation in Intermixed Polymer:PC₇₀BM Photovoltaic Blends: Correlating Structural and Photophysical Length Scales as a Function of Blend Composition