Processing additive suppresses phase separation in the active layer of organic photovoltaics based on naphthalene diimide

Mao, Zhenghao; Le, Thinh P.; Vakhshouri, Kiarash; Fernando, Roshan; Ruan, Fei; Muller, Evan; Gomez, Enrique D.; Sauvé, Geneviève

doi:10.1016/j.orgel.2014.09.021

Cited by 18 publications

(13 citation statements)

References 49 publications

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“…However, because of the low absorption in the visible region and the larger phase separation domains, when blended with the PBDTTT‐C‐T donor, the photoactive material obtained a low PCE performance of about 1.31% with a decreased J sc value of 2.7 mA cm −2 . In 2014, Mao et al reported a NDI based novel nonfullerene small molecule acceptor T49 where two cyclohexylaminos were at the bay position of the NDI molecule and the substituted group at the nitrogen atoms were thiophene base methyls instead of alkyl group . The UV–vis spectrum showed that this acceptor possessed a strong absorption area from 500 to 700 nm which was complementary with the P3HT donor.…”

Section: Nonfullerene Small Molecule Acceptorsmentioning

confidence: 99%

Recent Advances in Nonfullerene Acceptors for Organic Solar Cells

Liu

Hou

et al. 2017

Macromol. Rapid Commun.

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Recently, research on nonfullerene acceptors in organic solar cells has gradually become a hot topic due to such superior characteristics of light absorption and energy-level-convenient manipulation, multiformity of the photoactive material structures, as well as the extensive area in production compared to the fullerene derivatives. However, the nonfullerene acceptors evolved slowly before 2012 and, as a matter of fact, the power conversion efficiency values could only bear 2.0%. Strikingly, nonfullerene acceptors have developed at a fast pace since 2013, with the best device performance of 13.1% now. In this review, recent research progress on nonfullerene acceptors, including small molecules and polymers, are sorted and summarized on the basis of the different characteristics.

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Section: Nonfullerene Small Molecule Acceptorsmentioning

confidence: 99%

Recent Advances in Nonfullerene Acceptors for Organic Solar Cells

Liu

Hou

et al. 2017

Macromol. Rapid Commun.

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“…[52][53][54][55] However, since the high planarity and strong intermolecular interactions of PDIs lead to large-scale phase separation, one has to suppress the crystallinity of PDIs at the expense of electron mobility. [56][57][58][59][60] However, compared with PDI-based small molecules, NDI-based small molecules have not been extensively studied as acceptors in OPVs, with the exception of the NDI-thiophene oligomers reported by Sauvé and co-workers [ 61,62 ] and Jenekhe and co-workers, [ 63,64 ] which showed highest PCEs of 1.5%. Naphthalene diimides (NDIs), similar to PDIs, are extensively utilized as dye materials, providing a unique variability in structure modifi cation and a widely tunable absorption.…”

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confidence: 99%

NDI‐Based Small Molecule as Promising Nonfullerene Acceptor for Solution‐Processed Organic Photovoltaics

Liu

Zhang

Lee

et al. 2015

Advanced Energy Materials

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nonfullerene electron-accepting and electron-transporting materials is desirable to enhance the performance of OPVs. [35][36][37] Recently, several groups have reported novel nonfullerene small molecules as electron acceptors in solution-processed OPVs. [38][39][40][41][42][43][44][45][46][47][48][49] Among these materials, perylene diimide derivatives (PDIs) have widely been investigated [50][51][52][53][54][55] and have achieved power conversion effi ciencies (PCEs) as high as 6%. [52][53][54][55] However, since the high planarity and strong intermolecular interactions of PDIs lead to large-scale phase separation, one has to suppress the crystallinity of PDIs at the expense of electron mobility. [ 35,51 ] The greatest challenge in developing more effi cient nonfullerene acceptors in OPVs is the lack of good electron-transporting semiconductors that integrate solution processability with suitable energy levels and transport properties of the acceptors, and with molecular characteristics that can optimize the morphology. Naphthalene diimides (NDIs), similar to PDIs, are extensively utilized as dye materials, providing a unique variability in structure modifi cation and a widely tunable absorption. [56][57][58][59][60] However, compared with PDI-based small molecules, NDI-based small molecules have not been extensively studied as acceptors in OPVs, with the exception of the NDI-thiophene oligomers reported by Sauvé and co-workers [ 61,62 ] and Jenekhe and co-workers, [ 63,64 ] which showed highest PCEs of 1.5%. NDI is a versatile electron-defi cient building block that has been employed as a high electron mobility semiconductor. [ 65 ] Here, we designed and synthesized a novel dimer of NDI (BiNDI) using a vinyl linker ( Figure 1 A), which can extend the conjugation length, planarize the molecular backbone, and enhance the intermolecular π-π stacking. BiNDI exhibited an excellent electron transport property with a highest electron mobility of 0.365 cm 2 V −1 s −1 . OPVs by using BiNDI as the acceptor showed a highest PCE of 2.41%, which is the best result for NDI-based small molecular acceptors. Results and Discussion Material Synthesis and CharacterizationAs shown in Figure 1 A, BiNDI was synthesized by Stille coupling of monobromo-NDI and trans-1,2-bis(tributylstannyl) ethane in the presence of Pd(PPh 3 ) 4 . The reaction product is A novel naphthalene diimide (NDI)-based small molecule (BiNDI) is designed and synthesized by linking two NDI monomers via a vinyl donor moiety. The electronic structure of BiNDI is carefully investigated by ultraviolet photoelectron spectroscopy (UPS). Density functional theory (DFT) sheds further light on the molecular confi guration and energy level distribution. Thin fi lm transistors (TFT) based on BiNDI show a highest electron mobility of 0.365 cm 2 V −1 s −1 in ambient atmosphere. Organic photovoltaics (OPVs) by using BiNDI as the acceptor show a highest power conversion effi cency (PCE) of 2.41%, which is the best result for NDI-based small molecular acceptors. Transmission el...

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“…The black domain is assigned as the PC 71 BM aggregation because its ordered aggregation shows relatively higher electron scattering density compared to the amorphous polymer aggregation. 31 The blend lm with 5% PbS QDs doped exhibits rather compact bulk morphology which indicates the PC 71 BM aggregation decreases and homogeneous dispersion throughout the lm. It is benet to form better interpenetrating network structure in the bulk to promote the charge transport.…”

Section: Resultsmentioning

confidence: 96%