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1.
Layer‐by‐Layer Solution‐Processed Low‐Bandgap Polymer‐PC61BM Solar Cells with High Efficiency
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Polymer solar cells (PSCs) are fabricated without solvent additives using a low‐bandgap polymer, PBDTTT‐C‐T, as the donor and [6,6]‐phenyl‐C61‐butyric‐acid‐methyl‐ester (PC61BM) as the acceptor. Donor‐acceptor blend and layer‐by‐layer (LL) solution process are used to form active layers. Relative to the blend devices, the LL devices exhibit stronger absorption, better vertical phase separation, higher hole and electron mobilities, and better charge extraction at correct electrodes. As a result, after thermal annealing the LL devices exhibit an average power conversion efficiency (PCE) of 6.86%, which is much higher than that of the blend devices (4.31%). The best PCE of the LL devices is 7.13%, which is the highest reported for LL processed PSCs and among the highest reported for PC61BM‐based single‐junction PSCs. 相似文献
2.
A High‐Performance D–A Copolymer Based on Dithieno[3,2‐b:2′,3′‐d]Pyridin‐5(4H)‐One Unit Compatible with Fullerene and Nonfullerene Acceptors in Solar Cells
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Mingwei An Fangyuan Xie Xinjian Geng Jianqi Zhang Jiaxing Jiang Zhongli Lei Dan He Zuo Xiao Liming Ding 《Liver Transplantation》2017,7(14)
Development of high‐performance donor–acceptor (D–A) copolymers is vital in the research of polymer solar cells (PSCs). In this work, a low‐bandgap D–A copolymer based on dithieno[3,2‐b:2′,3′‐d]pyridin‐5(4H)‐one unit (DTP), PDTP4TFBT, is developed and used as the donor material for PSCs with PC71BM or ITIC as the acceptor. PDTP4TFBT:PC71BM and PDTP4TFBT:ITIC solar cells give power conversion efficiencies (PCEs) up to 8.75% and 7.58%, respectively. 1,8‐Diiodooctane affects film morphology and device performance for fullerene and nonfullerene solar cells. It inhibits the active materials from forming large domains and improves PCE for PDTP4TFBT:PC71BM cells, while it promotes the aggregation and deteriorates performance for PDTP4TFBT:ITIC cells. The ternary‐blend cells based on PDTP4TFBT:PC71BM:ITIC (1:1.2:0.3) give a decent PCE of 9.20%. 相似文献
3.
Tao Wang Nicholas W. Scarratt Hunan Yi Alan D. F. Dunbar Andrew J. Pearson Darren C. Watters Tom S. Glen Andrew C. Brook James Kingsley Alastair R. Buckley Maximilian W. A. Skoda Athene M. Donald Richard A. L. Jones Ahmed Iraqi David G. Lidzey 《Liver Transplantation》2013,3(4):505-512
We report the fabrication of high performance organic solar cells by spray‐coating the photoactive layer in air. The photovoltaic blends consist of a blend of carbazole and benzothiadiazole based donor–acceptor copolymers and the fullerene derivative PC70BM. Here, we formulate a number of photovoltaic inks using a range of solvent systems that we show can all be deposited by spray casting. We use a range of techniques to characterize the structure of such films, and show that spray‐cast films have comparable surface roughness to spin‐cast films and that vertical stratification that occurs during film drying reduces the concentration of PCBM towards the underlying PEDOT:PSS interface. We also show that the active layer thickness and the drying kinetics can be tuned through control of the substrate temperature. High power conversion efficiencies of 4.3%, 4.5% and 4.6% were obtained for solar cells made from a blend of PC70BM with the carbazole‐based co‐polymers PCDTBT, P2 and P1. By applying a low temperature anneal after the deposition of the cathode, the efficiency of spray‐cast solar‐cells based on a P2:PC70BM blend is increased to 5.0%. Spray coating holds significant promise as a technique capable of fabricating large‐area, high performance organic solar cells in air. 相似文献
4.
Toward High‐Temperature Stability of PTB7‐Based Bulk Heterojunction Solar Cells: Impact of Fullerene Size and Solvent Additive
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Sadok Ben Dkhil Martin Pfannmöller Maria Ilenia Saba Meriem Gaceur Hamed Heidari Christine Videlot‐Ackermann Olivier Margeat Antonio Guerrero Juan Bisquert Germa Garcia‐Belmonte Alessandro Mattoni Sara Bals Jörg Ackermann 《Liver Transplantation》2017,7(4)
The use of fullerene as acceptor limits the thermal stability of organic solar cells at high temperatures as their diffusion inside the donor leads to phase separation via Ostwald ripening. Here it is reported that fullerene diffusion is fully suppressed at temperatures up to 140 °C in bulk heterojunctions based on the benzodithiophene‐based polymer (the poly[[4,8‐bis[(2‐ethylhexyl)oxy]‐benzo[1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl][3‐fluoro‐2‐[(2‐ethylhexyl)carbonyl]‐thieno[3,4‐b]thiophenediyl]], (PTB7) in combination with the fullerene derivative [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC70BM). The blend stability is found independently of the presence of diiodooctane (DIO) used to optimize nanostructuration and in contrast to PTB7 blends using the smaller fullerene derivative PC70BM. The unprecedented thermal stability of PTB7:PC70BM layers is addressed to local minima in the mixing enthalpy of the blend forming stable phases that inhibit fullerene diffusion. Importantly, although the nanoscale morphology of DIO processed blends is thermally stable, corresponding devices show strong performance losses under thermal stress. Only by the use of a high temperature annealing step removing residual DIO from the device, remarkably stable high efficiency solar cells with performance losses less than 10% after a continuous annealing at 140 °C over 3 days are obtained. These results pave the way toward high temperature stable polymer solar cells using fullerene acceptors. 相似文献
5.
π‐Extended Narrow‐Bandgap Diketopyrrolopyrrole‐Based Oligomers for Solution‐Processed Inverted Organic Solar Cells
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Woong Shin Takuma Yasuda Yu Hidaka Go Watanabe Ryota Arai Keiro Nasu Takahiro Yamaguchi Wakako Murakami Kengo Makita Chihaya Adachi 《Liver Transplantation》2014,4(17)
A series of narrow‐bandgap π‐conjugated oligomers based on diketopyrrolopyrrole chromophoric units coupled with benzodithiophene, indacenodithiophene, thiophene, and isoindigo cores are designed and synthesized for application as donor materials in solution‐processed small‐molecule organic solar cells. The impacts of these different central cores on the optoelectronic and morphological properties, carrier mobility, and photovoltaic performance are investigated. These π‐extended oligomers possess broad and intense optical absorption covering the range from 550 to 750 nm, narrow optical bandgaps of 1.52–1.69 eV, and relatively low‐lying highest occupied molecular orbital (HOMO) energy levels ranging from ?5.24 to ?5.46 eV in their thin films. A high power conversion efficiency of 5.9% under simulated AM 1.5G illumination is achieved for inverted organic solar cells based on a small‐molecule bulk‐heterojunction system consisting of a benzodithiophene‐diketopyrrolopyrrole‐containing oligomer as a donor and [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC71BM) as an acceptor. Transmission electron microscopy and energy‐dispersive X‐ray spectroscopy reveal that interpenetrating and interconnected donor/acceptor domains with pronounced mesoscopic phase segregation are formed within the photoactive binary blends, which is ideal for efficient exciton dissociation and charge transport in the bulk‐heterojunction devices. 相似文献
6.
Safakath Karuthedath Yuliar Firdaus Ru‐Ze Liang Julien Gorenflot Pierre M. Beaujuge Thomas D. Anthopoulos Frdric Laquai 《Liver Transplantation》2019,9(33)
Ternary organic solar cells (OSCs) are among the best‐performing organic photovoltaic devices to date, largely due to the recent development of nonfullerene acceptors. However, fullerene molecules still play an important role in ternary OSC systems, since, for reasons not well understood, they often improve the device performance, despite their lack of absorption. Here, the photophysics of a prototypical ternary small‐molecule OSC blend composed of the donor DR3, the nonfullerene acceptor ICC6, and the fullerene derivative PC71BM is studied by ultrafast spectroscopy. Surprisingly, it is found that after excitation of PC71BM, ultrafast singlet energy transfer to ICC6 competes efficiently with charge transfer. Subsequently, singlets on ICC6 undergo hole transfer to DR3, resulting in free charge generation. Interestingly, PC71BM improves indirectly the electron mobility of the ternary blend, while electrons reside predominantly in ICC6 domains as indicated by fast spectroscopy. The improved mobility facilitates charge carrier extraction, in turn leading to higher device efficiencies of the ternary compared to binary solar cells. Using the (photo)physical parameters obtained from (transient) spectroscopy and charge transport measurements, the device's current–voltage characteristics are simulated and it is demonstrated that the parameters accurately reproduce the experimentally measured device performance. 相似文献
7.
Significantly Enhancing the Efficiency of a New Light‐Harvesting Polymer with Alkylthio naphthyl Substituents Compared to Their Alkoxyl Analogs
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Gongyue Huang Jun Zhang Nergui Uranbileg Weichao Chen Huanxiang Jiang Hua Tan Weiguo Zhu Renqiang Yang 《Liver Transplantation》2018,8(10)
In this work, a new benzo[1,2‐b:4,5‐b′]dithiophene (BDT) building block containing alkylthio naphthyl as a side chain is designed and synthesized, and the resulting polymer, namely PBDTNS‐BDD, shows a lower HOMO energy level than that of its alkoxyl naphthyl counterpart PBDTNO‐BDD. An optimized photovoltaic device using PBDTNS‐BDD as a donor exhibits power conversion efficiencies (PCE) of 8.70% and 9.28% with the fullerene derivative PC71BM and the fullerene‐free small molecule ITIC as acceptors, respectively. Surprisingly, ternary blend devices based on PBDTNS‐BDD and two acceptors, namely PC71BM and ITIC, shows a PCE of 11.21%, which is much higher than that of PBDTNO‐BDD based ternary devices (7.85%) even under optimized conditions. 相似文献
8.
Ultrafast Charge Generation Pathways in Photovoltaic Blends Based on Novel Star‐Shaped Conjugated Molecules
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Oleg V. Kozlov Yuriy N. Luponosov Sergei A. Ponomarenko Nina Kausch‐Busies Dmitry Yu Paraschuk Yoann Olivier David Beljonne Jérôme Cornil Maxim S. Pshenichnikov 《Liver Transplantation》2015,5(7)
The quest for new materials is one of the main factors propelling recent advances in organic photovoltaics. Star‐shaped small molecules (SSMs) have been proven promising candidates as perspective donor material due to the increase in numbers of excitation pathways caused by the degeneracy of the lowest unoccupied molecular orbital (LUMO) level. In order to unravel the pathways of the initial photon‐to‐charge conversion, the photovoltaic blends based on three different SSMs with a generic structure of N(phenylene‐nthiophene‐dicyanovinyl‐alkyl)3 (n = 1–3), and [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC71BM) acceptor are investigated by ultrafast photoinduced absorption spectroscopy assisted by density functional theory calculations. It is shown that both electron transfer from SSMs to PC71BM and hole transfer from PC71BM to SSMs are equally significant for generation of long‐lived charges. In contrast, intramolecular (intra‐SSM) charge separation results in geminate recombination and therefore constitutes a loss channel. Overall, up to 60% of long‐lived separated charges are generated at the optimal PC71BM concentrations. The obtained results suggest that further improvement of the SSM‐based solar cells is feasible via optimization of blend morphology and by suppressing the intra‐SSM recombination channel. 相似文献
9.
Dan Li Zuo Xiao Shizhe Wang Xinjian Geng Shangfeng Yang Junfeng Fang Huai Yang Liming Ding 《Liver Transplantation》2018,8(20)
An aromatic lactam acceptor unit, thieno[3,2‐c]isoquinolin‐5(4H)‐one (TIQ), is developed. Compared with its analogues, dithieno[3,2‐b:2′,3′‐d]pyridin‐5(4H)‐one (DTP) and phenanthridin‐6(5H)‐one (PN), TIQ shows its advantage in constructing donor–acceptor (D–A) copolymers for efficient solar cells. TIQ‐based D–A copolymer PTIQ4TFBT delivers a power conversion efficiency (PCE) of 10.16% in polymer:fullerene solar cells, while those based on DTP and PN copolymers, PDTP4TFBT and PPN4TFBT, afford PCEs around 8.5%. The higher performance of PTIQ4TFBT:PC71BM solar cells originates from enhanced short‐circuit current density (Jsc) and fill factor (FF), because of favorable morphology, less bimolecular recombination, and balanced charge transport in the active layer. Moreover, the performance for PTIQ4TFBT:PC71BM solar cells is less sensitive to active layer thickness than PDTP4TFBT:PC71BM and PPN4TFBT:PC71BM solar cells. Over 8% PCEs can be obtained from PTIQ4TFBT:PC71BM solar cells when the active layer thickness is over 500 nm. 相似文献
10.
Enhanced Photovoltaic Performance of Amorphous Donor–Acceptor Copolymers Based on Fluorine‐Substituted Benzodioxocyclohexene‐Annelated Thiophene
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Yutaka Ie Koki Morikawa Wojciech Zajaczkowski Wojciech Pisula Naresh B. Kotadiya Gert‐Jan A. H. Wetzelaer Paul W. M. Blom Yoshio Aso 《Liver Transplantation》2018,8(13)
Donor–acceptor (D‐A) type π‐conjugated copolymers with crystalline behavior have been extensively investigated as donor semiconductors in organic photovoltaics (OPVs). On the other hand, the development of high‐performance amorphous donor materials is still behind. The amorphous donor copolymer DTS‐C0(F2) consisting of dithieno[3,2‐b:2′,3′‐d]silole ( DTS ) donor unit and the recently developed fluorine‐substituted naphtho[2,3‐c]thiophene‐4,9‐dione ( C0(F2) ) acceptor unit shows moderate photovoltaic performance upon blending with PC71BM. In this work, to enhance the hole‐transporting characteristics, a 3‐hexylthiophene ( HT ) spacer unit is integrated into the conjugated backbone, resulting in a new amorphous copolymer DTS‐HT‐C0(F2) . The strong electron‐accepting nature of C0(F2) allows the introduction of the HT spacer without affecting the frontier orbital energies and thus the D‐A character. Without using solvent additives and thermal annealing, OPVs based on DTS‐HT‐C0(F2) and [6,6]‐phenyl‐C71‐butyric acid methyl ester PC71BM show an improved power conversion efficiency of 9.12%. Investigation of the device physics unambiguously reveals that the hole mobility of the copolymer in the blend is increased by an order of magnitude by the introduction of HT , while keeping an amorphous film nature, leading to higher short‐circuit current density and fill factor. These results demonstrate the realization of high‐performance OPVs based on amorphous active layers. 相似文献
11.
Ye Huang Xiaofeng Liu Cheng Wang James T. Rogers Gregory M. Su Michael L. Chabinyc Edward J. Kramer Guillermo C. Bazan 《Liver Transplantation》2014,4(10)
The ratio of the donor and acceptor components in bulk heterojunction (BHJ) organic solar cells is a key parameter for achieving optimal power conversion efficiency (PCE). However, it has been recently found that a few BHJ blends have compositional tolerance and achieve high performance in a wide range of donor to acceptor ratios. For instance, the X2 :PC61BM system, where X2 is a molecular donor of intermediate dimensions, exhibits a PCE of 6.6%. Its PCE is relatively insensitive to the blend ratio over the range from 7:3 to 4:6. The effect of blend ratio of X2 /PC61BM on morphology and device performance is therefore systematically investigated by using the structural characterization techniques of energy‐filtered transmission energy microscopy (EF‐TEM), resonant soft X‐ray scattering (R‐SoXS) and grazing incidence wide angle X‐ray scattering (GIWAXS). Changes in blend ratio do not lead to obvious differences in morphology, as revealed by R‐SoXS and EF‐TEM. Rather, there is a smooth evolution of a connected structure with decreasing domain spacing from 8:2 to 6:4 blend ratios. Domain spacing remains constant from 6:4 to 4:6 blend ratios, which suggests the presence of continuous phases with proper domain size that may provide access for charge carriers to reach their corresponding electrodes. 相似文献
12.
Brian J. Worfolk Tate C. Hauger Kenneth D. Harris David A. Rider Jordan A. M. Fordyce Serge Beaupré Mario Leclerc Jillian M. Buriak 《Liver Transplantation》2012,2(3):361-368
A water‐soluble cationic polythiophene derivative, poly[3‐(6‐{4‐tert‐butylpyridiniumyl}‐hexyl)thiophene‐2,5‐diyl] [P3(TBP)HT], is combined with anionic poly(3,4‐ethylenedioxythiophene):poly(p‐styrenesulfonate) (PEDOT:PSS) on indium tin oxide (ITO) substrates via electrostatic layer‐by‐layer (eLbL) assembly. By varying the number of eLbL layers, the electrode's work function is precisely controlled from 4.6 to 3.8 eV. These polymeric coatings are used as cathodic interfacial modifiers for inverted‐mode organic photovoltaics that incorporate a photoactive layer composed of either poly[(3‐hexylthiophene)‐2,5‐diyl] (P3HT) and the fullerene acceptor [6,6‐phenyl‐C61‐butyric acid methyl ester (PC61BM) or the low bandgap polymer [poly({4,8‐di(2‐ethylhexyloxyl)benzo[1,2‐b:4,5‐b′]dithiophene}‐2,6‐diyl)‐alt‐({5‐octylthieno[3,4‐c]pyrrole‐4,6‐dione}‐1,3‐diyl) (PBDTTPD)] and the electron acceptor [6,6‐phenyl‐C71‐butyric acid methyl ester (PC71BM)]. The power conversion efficiency (PCE) of the resulting photovoltaic device is dependent on the composition of the eLbL‐assembled interface and permits the fabrication of devices with efficiencies of 3.8% and 5.6% for P3HT and PBDTTPD donor polymers, respectively. Notably, these devices demonstrate significant stability with a P3HT:PC61BM system maintaining 83% of its original PCE after 1 year of storage and a PBDTTPD:PC71BM system maintaining 97% of its original PCE after over 1000 h of storage in air, according to the ISOS‐D‐1 shelf protocol. 相似文献
13.
In this study, a wavelength selective semitransparent polymer solar cell (ST‐PSC) with a proper transmission spectrum for plant growth is proposed for greenhouse applications. A ternary strategy combining a wide bandgap polymer donor with a near‐infrared absorbing nonfullerene acceptor and a high electron mobility fullerene acceptor is introduced to achieve PSCs with power conversion efficiency (PCE) over 10%. The addition of PC71BM into J52:IEICO‐4F binary blend contributes to the suppressed trap‐assisted recombination, enhanced charge extraction, and improved open‐circuit voltage simultaneously. ST‐PSC based on the J52:IEICO‐4F:PC71BM ternary blend shows an optimized performance with PCE of 7.75% and a defined crop growth factor of 24.8%. Such high‐performance ST‐PSC is achieved by carefully engineering the absorption spectrum of the light harvesting materials. As a result, the transmission spectra of the semitransparent devices are well‐matched with the absorption spectra of the photoreceptors, such as chlorophylls, in green plants, which provides adequate lighting conditions for photosynthesis and plant growth, and therefore making it a competitive candidate for photovoltaic greenhouse applications. 相似文献
14.
Benzo[1,2‐b:4,5‐b′]Dithiophene–6,7‐Difluoroquinoxaline Small Molecule Donors with >8% BHJ Solar Cell Efficiency
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Ru‐Ze Liang Kai Wang Jannic Wolf Maxime Babics Philipp Wucher Mohammad K. Al Thehaiban Pierre M. Beaujuge 《Liver Transplantation》2017,7(20)
Solution‐processable small molecule (SM) donors are promising alternatives to their polymer counterparts in bulk‐heterojunction (BHJ) solar cells. While SM donors with favorable spectral absorption, self‐assembly patterns, optimum thin‐film morphologies, and high carrier mobilities in optimized donor–acceptor blends are required to further BHJ device efficiencies, material structure governs each one of those attributes. As a result, the rational design of SM donors with gradually improved BHJ solar cell efficiencies must concurrently address: (i) bandgap tuning and optimization of spectral absorption (inherent to the SM main chain) and (ii) pendant‐group substitution promoting structural order and mediating morphological effects. In this paper, the rational pendant‐group substitution in benzo[1,2‐b:4,5‐b′]dithiophene–6,7‐difluoroquinoxaline SMs is shown to be an effective approach to narrowing the optical gap (Eopt) of the SM donors ( SM1 and SM2 ), without altering their propensity to order and form favorable thin‐film BHJ morphologies with PC71BM. Systematic device examinations show that power conversion efficiencies >8% and open‐circuit voltages (VOC) nearing 1 V can be achieved with the narrow‐gap SM donor analog ( SM2 , Eopt = 1.6 eV) and that charge transport in optimized BHJ solar cells proceeds with minimal, nearly trap‐free recombination. Detailed device simulations, light intensity dependence, and transient photocurrent analyses emphasize how carrier recombination impacts BHJ device performance upon optimization of active layer thickness and morphology. 相似文献
15.
Effect of Molecular Orientation of Donor Polymers on Charge Generation and Photovoltaic Properties in Bulk Heterojunction All‐Polymer Solar Cells
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All‐polymer solar cells (all‐PSCs) utilizing p‐type polymers as electron‐donors and n ‐typepolymers as electron‐acceptors have attracted a great deal of attention, and their efficiencies have been improved considerably. Here, five polymer donors with different molecular orientations are synthesized by random copolymerization of 5‐fluoro‐2,1,3‐benzothiadiazole with different relative amounts of 2,2′‐bithiophene (2T) and dithieno[3,2‐b;2′,3′‐d]thiophene (DTT). Solar cells are prepared by blending the polymer donors with a naphthalene diimide‐based polymer acceptor (PNDI) or a [6,6]‐phenyl C71‐butyric acid methyl ester (PC71BM) acceptor and their morphologies and crystallinity as well as optoelectronic, charge‐transport and photovoltaic properties are studied. Interestingly, charge generation in the solar cells is found to show higher dependence on the crystal orientation of the donor polymer for the PNDI‐based all‐PSCs than for the conventional PC71BM‐based PSCs. As the population of face‐on‐oriented crystallites of the donor increased in PNDI‐based PSC, the short‐circuit current density (JSC) and external quantum efficiency of the devices are found to significantly improve. Consequently, device efficiency was enhanced of all‐PSC from 3.11% to 6.01%. The study reveals that producing the same crystal orientation between the polymer donor and acceptor (face‐on/face‐on) is important in all‐PSCs because they provide efficient charge transfer at the donor/acceptor interface. 相似文献
16.
Efficient conventional bulk heterojunction (BHJ) perovskite hybrid solar cells (pero‐HSCs) solution‐processed from a composite of CH3NH3PbI3 mixed with PC61BM ([6,6]‐phenyl‐C61‐butyric acid methyl ester), where CH3NH3PbI3 acts as the electron donor and PC61BM acts as the electron acceptor, are reported for the first time. The efficiency of 12.78% is twofold enhancement in comparison with the conventional planar heterojunction pero‐HSCs (6.90%) fabricated by pristine CH3NH3PbI3. The BHJ pero‐HSCs are further optimized by using PC61BM/TiO2 bi‐electron‐extraction‐layer (EEL), which are both solution‐processed and then followed with low‐temperature thermal annealing. Due to higher electrical conductivity of PC61BM over that of TiO2, an efficiency of 14.98%, the highest reported efficiency for the pero‐HSCs without incorporating high‐temperature‐processed mesoporous TiO2 and Al2O3 as the EEL and insulating scaffold, is observed from PC61BM modified BHJ pero‐HSCs. Thus, the findings provide a simple way to approach high efficiency low‐cost pero‐HSCs. 相似文献
17.
Effects of Shortened Alkyl Chains on Solution‐Processable Small Molecules with Oxo‐Alkylated Nitrile End‐Capped Acceptors for High‐Performance Organic Solar Cells
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Solution‐processable small molecules are significant for producing high‐performance bulk heterojunction organic solar cells (OSCs). Shortening alkyl chains, while ensuring proper miscibility with fullerene, enables modulation of molecular stacking, which is an effective method for improving device performance. Here, the design and synthesis of two solution‐processable small molecules based on a conjugated backbone with a novel end‐capped acceptor (oxo–alkylated nitrile) using octyl and hexyl chains attached to π–bridge, and octyl and pentyl chains attached to the acceptor is reported. Shortening the length of the widely used octyl chains improves self‐assembly and device performance. Differential scanning calorimetry and grazing incidence X‐ray diffraction results demonstrated that the molecule substituted by shorter chains shows tighter molecular stacking and higher crystallinity in the mixture with 6,6‐phenyl‐C71‐butyric acid methyl ester (PC71BM) and that the power conversion efficiency (PCE) of the OSC is as high as 5.6% with an open circuit voltage (Voc) of 0.87 V, a current density (Jsc) of 9.94 mA cm‐2, and an impressive filled factor (FF) of 65% in optimized devices. These findings provide valuable insights into the production of highly efficient solution‐processable small molecules for OSCs. 相似文献
18.
Remarkably High Conversion Efficiency of Inverted Bulk Heterojunction Solar Cells: From Ultrafast Laser Spectroscopy and Electron Microscopy to Device Fabrication and Optimization
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Qana A. Alsulami Banavoth Murali Yara Alsinan Manas R. Parida Shawkat M. Aly Omar F. Mohammed 《Liver Transplantation》2016,6(11)
19.
John G. Labram James Kirkpatrick Donal D. C. Bradley Thomas D. Anthopoulos 《Liver Transplantation》2011,1(6):1176-1183
The clustering and diffusion of C71‐butyric acid methyl ester (PC71BM) in poly(3‐hexylthiophene) (P3HT) has been studied using single layer blend and bilayer organic field‐effect transistors (OFETs) and by atomic force microscopy (AFM). P3HT:PC71BM blend based OFETs were found to undergo phase‐segregation upon annealing, which was detectable as a fall in electron mobility with increasing annealing temperature. By employing carefully designed bilayer P3HT:PC71BM OFETs, the diffusion‐properties of PC71BM in P3HT could additionally be inferred from electron mobility measurements. It was found that the prerequisite annealing temperatures for detectable PC71BM clustering and diffusion in P3HT was approximately 20 °C higher than for PC61BM. The diffusion coefficient of PC61BM in P3HT was found to be several times higher that that of PC71BM. The present work provides unique insights into the diffusion process of fullerenes in conjugated polymers and could prove highly valuable for future materials development and device optimization. 相似文献
20.
Photovoltaic performance of polymer solar cells based on poly(3‐hexylthiophene) (P3HT) as the donor and indene‐C70 bisadduct (IC70BA) as the acceptor is improved by adding 3 vol% 3‐methylthiophene (MT) or 3‐hexylthiophene (HT) as processing additives. The results of UV‐vis absorption spectroscopy, X‐ray diffraction analysis and atomic force microscopy indicate that with the MT or HT processing additive, the active layer of the blend of P3HT/IC70BA showed strengthened absorbance, enhanced crystallinity and improved film morphology. The power conversion efficiency (PCE) of the PSCs was improved from 5.80% for the device without the additive to 6.35% for the device with HT additive and to 6.69% with MT additive. The PCE of 6.69% is the top value reported so far for the PSCs based on P3HT. 相似文献