Effects of the Number of Bromine Substitution on Photovoltaic Efficiency and Energy Loss of Benzo[1,2‐b:4,5‐b′]diselenophene‐based Narrow‐Bandgap Multibrominated Nonfullerene Acceptors

Wan, Shi‐Sheng; Chang, Chen; Wang, Jin‐Liang; Yuan, Guizhou; Wu, Qing; Zhang, Maojie; Li, Yongfang

doi:10.1002/solr.201800250

Cited by 50 publications

(37 citation statements)

References 90 publications

(133 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In comparison with thiophene‐based A–D–A‐type nonfullerene SMAs, selenophene‐based A–D–A‐type nonfullerene SMAs received relatively less attention . In fact, selenophene possessed several merits relative to thiophene.…”

Section: Asymmetric A–d–a‐type Nonfullerene Smasmentioning

confidence: 99%

Asymmetric Nonfullerene Small Molecule Acceptors for Organic Solar Cells

Xia

et al. 2019

Advanced Energy Materials

209

164

View full text Add to dashboard Cite

EDPD acceptors, respectively. Since then, several promising asymmetric nonfullerene SMAs have been developed to pair with the polymer donor P3HT. [39][40][41][42][43] However, the development of asymmetric nonfullerene SMAs remained nearly stagnant from 2015 to 2016. This unfavorable situation has changed when asymmetric nonfullerene SMAs began to emerge in 2017 and experienced rapid development in the past 3 years. [32][33][34][35][36][37] In addition to maintaining the advantages of symmetric nonfullerene SMAs, [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] such as chemical structure diversity and good adjustability in photoelectrical properties, asymmetric nonfullerene SMAs may additionally exhibit stronger intermolecular binding energy and larger dipole moment than symmetric nonfullerene SMA counterparts. [33,35,44] Both stronger intermolecular binding energy and larger dipole moment are beneficial to reinforce intermolecular interaction, rendering asymmetric nonfullerene SMAs a promising class of nonfullerene SMAs to increase the fill factor (FF) and power conversion efficiency (PCE) in OSCs. To date, the PCEs of OSCs based on asymmetric nonfullerene SMAs have gradually increased from 1.27% in 2010 to nearly 14% in 2019. [31,38] There have been a large number of review articles summarizing the recent development of symmetric nonfullerene SMAs. [13][14][15][16][17][18][45][46][47][48][49][50][51] However, to the best of our knowledge, there has been no one review article specially focusing on asymmetric nonfullerene SMAs so far. Given the significant progress achieved recently for asymmetric nonfullerene SMAs, it is timely to briefly review the development of asymmetric nonfullerene SMAs in the past decade. Here, we first summarize the recent advances of asymmetric nonfullerene SMAs, including early reports of asymmetric nonfullerene SMAs, asymmetric PDI-based nonfullerene SMAs, and asymmetric acceptor-donor-acceptor (A-D-A)-type nonfullerene SMAs. Finally, we discuss the structure-property relationships and the perspectives for future development of asymmetric nonfullerene SMAs. Early Reports of Asymmetric Nonfullerene SMAsIn view of the shortcomings of asymmetric fullerene SMAs, some attempts have been made to develop asymmetric nonfullerene SMAs with easy access, tunable optical/electrochemical properties, and wide possibility of functionalization. [39][40][41][42][43] Generally, these asymmetric nonfullerene SMAs could be Symmetry breaking provides a new material design strategy for nonfullerene small molecule acceptors (SMAs). The past 10 years have witnessed significant advances in asymmetric nonfullerene SMAs in organic solar cells (OSCs) with power conversion efficiency (PCE) increasing from ≈1% to ≈14%. In this review, the progress of asymmetric nonfullerene SMAs, including early reports of asymmetric nonfullerene SMAs, asymmetric PDI-based nonfullerene SMAs, and asymmetric acceptor-donor-acceptor (A-D-A)-type nonfullerene SMAs, is summarized. The structure-property relation...

show abstract

Section: Asymmetric A–d–a‐type Nonfullerene Smasmentioning

confidence: 99%

Asymmetric Nonfullerene Small Molecule Acceptors for Organic Solar Cells

Xia

et al. 2019

Advanced Energy Materials

209

164

View full text Add to dashboard Cite

show abstract

“…The synthetic routes of TSeIC4Cl and TSeIC4Br were shown in the Scheme and the detailed syntheses were provided in Supporting Information. TSeIC4Cl and TSeIC4Br were synthesized by the Knoevenagel condensation reaction between the central unit TSe‐2CHO [ 86 ] and dichloro‐substituted IC end group ( IC2Cl ) [ 87 ] or dibromo‐substituted IC end group ( IC2Br ) [ 77 ] with isolated yields of 91% and 85%, respectively. Their exact chemical structures are confirmed by 1 H NMR, 13 C NMR, and MALDI‐TOF‐MS, which were shown in support information.…”

Section: Resultsmentioning

confidence: 99%

“…Halogenation at the core unit or at the end group of the NF‐SMAs with different number of halogen atoms or in different substituted position/aromatic groups is a significantly effective strategy to modulate molecular energy levels and absorption range and improve the blend morphology and device performance. [ 66–80 ] Compared with the popular fluorinated or chlorinated IC functionalized NF‐SMAs, although brominated NF‐SMAs show lower synthesis cost and are much easier for postmodification, the brominated IC has been less incorporated into NF‐SMAs. [ 14,69,70,79,80 ] Until recently, Prof. Li's and Prof. Chen's groups independently reported the monobrominated IC functionalized NF‐SMAs with different core unit, which both exhibited slightly higher PCE in comparison with corresponding monofluorinated IC functionalized NF‐SMAs.…”

Section: Introductionmentioning

confidence: 99%

“…In our previous work, we first synthesized the dibrominated IC and systematically investigated the effect of different number of bromine atoms (0, 2, 4) functionalized NF‐SMAs on the film morphology, photovoltaic performance of these NF‐SMAs, and polymeric donor materials. [ 77 ] Although we only achieved moderate PCE for dibrominated IC‐based NF‐SMAs due to the unsatisfactory blend morphology, there is great room to improve after further structural and device optimization. Thus, it is necessary to develop new highly efficient dibrominated IC‐based NF‐SMAs with appropriate central unit to better understand the structure–performance relationship of NF‐SMAs‐based PSCs.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Tetrabromination versus Tetrachlorination: A Molecular Terminal Engineering of Nonfluorinated Acceptors to Control Aggregation for Highly Efficient Polymer Solar Cells with Increased V_oc and Higher J_sc Simultaneously

et al. 2020

View full text Add to dashboard Cite

Polymer solar cells (PSCs) have achieved a huge breakthrough in the past 5 years with the combinational contributions from the developments of nonfullerene acceptors (NFAs), polymeric donors, and kind of redundant of device engineering. [1-12] Compared with traditional fullerene acceptors, AD A framework nonfullerene small molecular acceptors (NF-SMAs) have significant advantages in broader absorption range, tunable molecular structure and energy levels, and diversified donor materials for matching. [13-23] Therefore, many such typed NF-SMAs have been synthesized and become the mainstream materials for the development of high-efficiency PSCs. [24-36] Recently, the power conversion efficiencies (PCEs) of NF-SMAs-based PSCs have been sharply increased over 16% in single-junction binary and ternary devices, indicating their great potentials for further practical application. [37-57] NF-SMAs, such as ITIC and Y6, typically comprise an electron-rich fused core, side chain group, and electron-deficient terminal groups, and all of which can be modified by introducing functional groups or atoms to better understand the structureproperty relationship and improve the device performance of ITIC or Y6 series-based PSCs. [58,59] Molecular engineering on ending groups of NF-SMAs, typically, is the last synthetic step in the synthesis of NF-SMAs and mainly contributed to the intermolecular packing, which played a vital role in optimizing the electronic and morphological properties as well as in enhancing charge transport and device performance. [60-65] Halogenation at the core unit or at the end group of the NF-SMAs with different number of halogen atoms or in different substituted position/aromatic groups is a significantly effective strategy to modulate molecular energy levels and absorption range and improve the blend morphology and device performance. [66-80] Compared with the popular fluorinated or chlorinated IC functionalized NF-SMAs, although brominated NF-SMAs show lower synthesis cost and are much easier for

show abstract

“…If the A units are modified with electron‐withdrawing groups, the LUMO energy level would be reduced, leading to a low V oc for PSCs . But it is the mostly used strategy in designing A unit due to it beneficial for red‐shifting absorption spectra and enhancing crystallinity property of NFAs, which are favorable for high J sc and FF . Meanwhile, the D core also plays a key role in adjusting the

E_{normalg}^{opt}

s and energy levels of NFAs.…”

Section: Introductionmentioning

confidence: 99%

A Novel Carbazole‐Based Nonfullerene Acceptor for High‐Efficiency Polymer Solar Cells

et al. 2019

View full text Add to dashboard Cite

It is important to tune the energy levels of nonfullerene acceptors (NFAs) to achieve more balanced open‐circuit voltage (Voc) and short‐circuit current density (Jsc) to improve the device performance. Herein, two novel NFAs are designed via fusing fluorene or carbazole with two thieno[3,2‐b]thiophene and end capped with INIC‐2F, namely, 4TFIC‐4F and 4TCIC‐4F, respectively. The impact of the fluorene and carbazole unit on the PSC performance is systematically studied. Compared with 4TFIC‐4F, 4TCIC‐4F exhibits a higher lowest unoccupied molecular orbital (LUMO) energy level of −3.95 eV and a narrower optical bandgap of 1.51 eV owing to the stronger electron‐donating capacity of fused‐carbazole ring core. Consequently, the 4TCIC‐4F device achieves a high power conversion efficiencies (PCE) of 13.02% with a higher Voc of 0.94 V and a larger Jsc of 18.98 mA cm−2, whereas the 4TFIC‐4F device shows a PCE of 11.24%. The PCE of 13.02% is the highest value so far reported with the carbazole‐containing NFAs‐based PSCs. More importantly, the 4TCIC‐4F device shows good film thickness insensitive and long‐term thermal stability. The investigation demonstrates that the fused‐carbazole ring is a superior option to fused‐fluorene ring as electron‐donating core for designing high‐performance NFAs by improving Voc and Jsc simultaneously.

show abstract

Effects of the Number of Bromine Substitution on Photovoltaic Efficiency and Energy Loss of Benzo[1,2‐b:4,5‐b′]diselenophene‐based Narrow‐Bandgap Multibrominated Nonfullerene Acceptors

Cited by 50 publications

References 90 publications

Asymmetric Nonfullerene Small Molecule Acceptors for Organic Solar Cells

Asymmetric Nonfullerene Small Molecule Acceptors for Organic Solar Cells

Tetrabromination versus Tetrachlorination: A Molecular Terminal Engineering of Nonfluorinated Acceptors to Control Aggregation for Highly Efficient Polymer Solar Cells with Increased V_oc and Higher J_sc Simultaneously

A Novel Carbazole‐Based Nonfullerene Acceptor for High‐Efficiency Polymer Solar Cells

Contact Info

Product

Resources

About

Effects of the Number of Bromine Substitution on Photovoltaic Efficiency and Energy Loss of Benzo[1,2‐b:4,5‐b′]diselenophene‐based Narrow‐Bandgap Multibrominated Nonfullerene Acceptors

Cited by 50 publications

References 90 publications

Asymmetric Nonfullerene Small Molecule Acceptors for Organic Solar Cells

Asymmetric Nonfullerene Small Molecule Acceptors for Organic Solar Cells

Tetrabromination versus Tetrachlorination: A Molecular Terminal Engineering of Nonfluorinated Acceptors to Control Aggregation for Highly Efficient Polymer Solar Cells with Increased Voc and Higher Jsc Simultaneously

A Novel Carbazole‐Based Nonfullerene Acceptor for High‐Efficiency Polymer Solar Cells

Contact Info

Product

Resources

About

Tetrabromination versus Tetrachlorination: A Molecular Terminal Engineering of Nonfluorinated Acceptors to Control Aggregation for Highly Efficient Polymer Solar Cells with Increased V_oc and Higher J_sc Simultaneously