Efficient Ternary Polymer Solar Cells with Two Well‐Compatible Donors and One Ultranarrow Bandgap Nonfullerene Acceptor

Nonfullerene polymer solar cells (PSCs) are fabricated by using one wide bandgap donor PBDB‐T and one ultranarrow bandgap acceptor IEICO‐4F as the active layers. One medium bandgap donor PTB7‐Th is selected as the third component due to the similar highest occupied molecular orbital level compared to that of PBDB‐T and their complementary absorption spectra. The champion power conversion efficiency (PCE) of PSCs is increased from 10.25% to 11.62% via incorporating 20 wt% PTB7‐Th in donors, with enhanced short‐circuit current (J_SC) of 24.14 mA cm^?2 and fill factor (FF) of 65.03%. The 11.62% PCE should be the highest value for ternary nonfullerene PSCs. The main contribution of PTB7‐Th can be summarized as the improved photon harvesting and enhanced exciton utilization of PBDB‐T due to the efficient energy transfer from PBDB‐T to PTB7‐Th. Meanwhile, PTB7‐Th can also act as a regulator to adjust PBDB‐T molecular arrangement for optimizing charge transport, resulting in the enhanced FF of ternary PSCs. This experimental result may provide new insight for developing high‐performance ternary nonfullerene PSCs by selecting two well‐compatible donors with different bandgap and one ultranarrow bandgap acceptor.     

Green‐Solvent‐Processed All‐Polymer Solar Cells Containing a Perylene Diimide‐Based Acceptor with an Efficiency over 6.5%

To realize high power conversion efficiencies (PCEs) in green‐solvent‐processed all‐polymer solar cells (All‐PSCs), a long alkyl chain modified perylene diimide (PDI)‐based polymer acceptor PPDIODT with superior solubility in nonhalogenated solvents is synthesized. A properly matched PBDT‐TS1 is selected as the polymer donor due to the red‐shifted light absorption and low‐lying energy level in order to achieve the complementary absorption spectrum and matched energy level between polymer donor and polymer acceptor. By utilizing anisole as the processing solvent, an optimal efficiency of 5.43% is realized in PBDT‐TS1/PPDIODT‐based All‐PSC with conventional configuration, which is comparable with that of All‐PSCs processed by the widely used binary solvent. Due to the utilization of an inverted device configuration, the PCE is further increased to over 6.5% efficiency. Notably, the best‐performing PCE of 6.58% is the highest value for All‐PSCs employing PDI‐based polymer acceptors and green‐solvent‐processed All‐PSCs. The excellent photovoltaic performance is mainly attributed to a favorable vertical phase distribution, a higher exciton dissociation efficiency (P_diss) in the blend film, and a higher electrode carrier collection efficiency. Overall, the combination of rational molecular designing, material selection, and device engineering will motivate the efficiency breakthrough in green‐solvent‐processed All‐PSCs.     

Effect of Molecular Orientation of Donor Polymers on Charge Generation and Photovoltaic Properties in Bulk Heterojunction All‐Polymer Solar Cells

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 (J_SC) 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.     

High‐Performance and Stable All‐Polymer Solar Cells Using Donor and Acceptor Polymers with Complementary Absorption

To explore the advantages of emerging all‐polymer solar cells (all‐PSCs), growing efforts have been devoted to developing matched donor and acceptor polymers to outperform fullerene‐based PSCs. In this work, a detailed characterization and comparison of all‐PSCs using a set of donor and acceptor polymers with both conventional and inverted device structures is performed. A simple method to quantify the actual composition and light harvesting contributions from the individual donor and acceptor is described. Detailed study on the exciton dissociation and charge recombination is carried out by a set of measurements to understand the photocurrent loss. It is unraveled that fine‐tuned crystallinity of the acceptor, matched donor and acceptor with complementary absorption and desired energy levels, and device architecture engineering can synergistically boost the performance of all‐PSCs. As expected, the PBDTTS‐FTAZ:PNDI‐T10 all‐PSC attains a high and stable power conversion efficiency of 6.9% without obvious efficiency decay in 60 d. This work demonstrates that PNDI‐T10 can be a potential alternative acceptor polymer to the widely used acceptor N2200 for high‐performance and stable all‐PSCs.     

8.0% Efficient All‐Polymer Solar Cells with High Photovoltage of 1.1 V and Internal Quantum Efficiency near Unity

In very recent years, growing efforts have been devoted to the development of all‐polymer solar cells (all‐PSCs). One of the advantages of all‐PSCs over the fullerene‐based PSCs is the versatile design of both donor and acceptor polymers which allows the optimization of energy levels to maximize the open‐circuit voltage (V_oc). However, there is no successful example of all‐PSCs with both high V_oc over 1 V and high power conversion efficiency (PCE) up to 8% reported so far. In this work, a combination of a donor polymer poly[4,8‐bis(5‐(2‐octylthio)thiophen‐2‐yl)benzo[1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl‐alt‐(5‐(2‐ethylhexyl)‐4H‐thieno[3,4‐c]pyrrole‐4,6(5H)‐dione)‐1,3‐diyl] (PBDTS‐TPD) with a low‐lying highest occupied molecular orbital level and an acceptor polymer poly[[N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐thiophene‐2,5‐diyl] (PNDI‐T) with a high‐lying lowest unoccupied molecular orbital level is used, realizing high‐performance all‐PSCs with simultaneously high V_oc of 1.1 V and high PCE of 8.0%, and surpassing the performance of the corresponding PC₇₁BM‐based PSCs. The PBDTS‐TPD:PNDI‐T all‐PSCs achieve a maximum internal quantum efficiency of 95% at 450 nm, which reveals that almost all the absorbed photons can be converted into free charges and collected by electrodes. This work demonstrates the advantages of all‐PSCs by incorporating proper donor and acceptor polymers to boost both V_oc and PCEs.     

Improved Tandem All‐Polymer Solar Cells Performance by Using Spectrally Matched Subcells

All‐polymer solar cells (all‐PSCs) are attractive as alternatives to fabricate thermally and mechanically stable solar cells, especially with recent improvements in their power conversion efficiency (PCE). In this work, efficient all‐PSCs with near‐infrared response (up to 850 nm) are developed using newly designed regioregular polymer donors with relatively narrow optical gap. These all‐PSCs systems achieve PCEs up to 6.0% after incorporating fluorine into the polymer backbone. More importantly, these polymers exhibit absorbance that is complementary to previously reported wide bandgap polymer donors. Thus, the superior properties of the newly designed polymers afford opportunities to fabricate the first spectrally matched all‐polymer tandem solar cells with high performance. A PCE of 8.3% is then demonstrated which is the highest efficiency so far for all‐polymer tandem solar cells. The design of narrow bandgap polymers provides new directions to enhance the PCE of emerging single‐junction and tandem all polymer solar cells.     

Liquid‐Crystalline Small Molecules for Nonfullerene Solar Cells with High Fill Factors and Power Conversion Efficiencies

Compared with nonfullerene‐based polymer solar cells, all‐small‐molecule solar cells normally show low power conversion efficiencies (PCEs) due to their low fill factors (FFs). Molecular stacking orientation and phase separation are the main factors affecting the performance of all‐small‐molecule solar cells. In this work, two liquid‐crystalline small‐molecule donors are designed and synthesized and a novel nonfullerene acceptor with good crystallinity developed. Owing to the face‐on orientation of the component molecules and appropriate phase separation in the active layer, a high FF of over 70% and a PCE of 10.7% are obtained from the resulting solar cells; these values are among the best obtained thus far for all‐small‐molecule solar cells. The high FF reported here is significant for a further design of high‐performance all‐small‐molecule solar cells.     

Tuning Energy Levels without Negatively Affecting Morphology: A Promising Approach to Achieving Optimal Energetic Match and Efficient Nonfullerene Polymer Solar Cells

One advantage of nonfullerene polymer solar cells (PSCs) is that they can yield high open‐circuit voltage (V_OC) despite their relatively low optical bandgaps. To maximize the V_OC of PSCs, it is important to fine‐tune the energy level offset between the donor and acceptor materials, but in a way not negatively affecting the morphology of the donor:acceptor (D:A) blends. Here, an effective material design rationale based on a family of D–A1–D–A2 terthiophene (T3) donor polymers is reported, which allows for the effective tuning of energy levels but without any negative impacts on the morphology of the blend. Based on a T3 donor unit combined with difluorobenzothiadiazole (ffBT) and difluorobenzoxadiazole (ffBX) acceptor units, three donor polymers are developed with highly similar morphological properties. This is particularly surprising considering that the corresponding quaterthiophene polymers based on ffBT and ffBX exhibit dramatic differences in their solubility and morphological properties. With the fine‐tuning of energy levels, the T3 polymers yield nonfullerene PSCs with a high efficiency of 9.0% for one case and with a remarkably low energy loss (0.53 V) for another polymer. This work will facilitate the development of efficient nonfullerene PSCs with optimal energy levels and favorable morphology properties.     

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

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%.     

3,4‐Dicyanothiophene—a Versatile Building Block for Efficient Nonfullerene Polymer Solar Cells

In this contribution, a versatile building block, 3,4‐dicyanothiophene (DCT), which possesses structural simplicity and synthetic accessibility for constructing high‐performance, low‐cost, wide‐bandgap conjugated polymers for use as donors in polymer solar cells (PSCs), is reported. A prototype polymer, PB3TCN‐C66, and its cyano‐free analogue polymer PB3T‐C66, are synthesized to evaluate the potential of using DCT in nonfullerene PSCs. A stronger aggregation property in solution, higher thermal transition temperatures with higher enthalpies, a larger dipole moment, higher relative dielectric constant, and more linear conformation are exhibited by PB3TCN‐C66. Solar cells employing IT‐4F as the electron acceptor offer power conversion efficiencies (PCEs) of 11.2% and 2.3% for PB3TCN‐C66 and PB3T‐C66, respectively. Morphological characterizations reveal that the PB3TCN‐C66:IT‐4F blend exhibits better π–π paracrystallinity, a contracted domain size, and higher phase purity, consistent with its higher molecular interaction parameter, derived from thermodynamic calculations. Moreover, PB3TCN‐C66 offers a higher open‐circuit voltage and reduced energy loss than most state‐of‐the‐art wide‐bandgap polymers, without the need of additional electron‐withdrawing substituents. Two additional polymers derived from DCT also demonstrate promising performance with a higher PCE of 13.4% being achieved. Thus, DCT represents a versatile and promising building block for constructing high‐performance, low‐cost, conjugated polymers for application in PSCs.     

Improvement of Photovoltaic Performance of Polymer Solar Cells by Rational Molecular Optimization of Organic Molecule Acceptors

Two n‐type organic semiconductor (n‐OS) small molecules m‐ITIC‐2F and m‐ITIC‐4F with fluorinated 2‐(2,3‐dihydro‐3‐oxo‐1H‐inden‐1‐ylidene)propanedinitrile (IC) terminal moieties are prepared, for the application as an acceptor in polymer solar cells (PSCs), to further improve the photovoltaic performance of the n‐OS acceptor 3,9‐bis(2‐methylene‐(3‐(1,1‐dicyanomethylene) indanone) ‐5,5,11,11‐tetrakis(3‐hexylphenyl)‐dithieno[2,3‐d:2′,3′‐d′]‐sindaceno[1,2‐b:5,6‐b′]‐dithiophene (m‐ITIC). Compared to m‐ITIC, these two new acceptors show redshifted absorption, higher molecular packing order, and improved electron mobilities. The power conversion efficiencies (PCE) of the as‐cast PSCs with m‐ITIC‐2F or m‐ITIC‐4F as an acceptor and a low‐cost donor–acceptor (D–A) copolymer PTQ10 as a donor reach 11.57% and 11.64%, respectively, which are among the highest efficiency for the as‐cast PSCs so far. Furthermore, after thermal annealing treatment, improved molecular packing and enhanced phase separation are observed, and the higher PCE of 12.53% is achieved for both PSCs based on the two acceptors. The respective and unique advantage with the intrinsic high degree of order, molecular packing, and electron mobilities of these two acceptors will be suitable to match with different p‐type organic semiconductor donors for higher PCE values, which provide a great potential for the PSCs commercialization in the near future. These results indicate that rational molecular structure optimization is of great importance to further improve photovoltaic properties of the photovoltaic materials.     

Solution‐Processed Polymer Solar Cells with over 17% Efficiency Enabled by an Iridium Complexation Approach

The commercially available PM6 as donor materials are used widely in highly efficient nonfullerene polymer solar cells (PSCs). In this work, different concentrations of iridium (Ir) complexes (0, 0.5, 1, 2.5, and 5 mol%) are incorporated carefully into the polymer conjugated backbone of PM6 (PM6‐Ir0), and a set of π‐conjugated polymer donors (named PM6‐Ir0.5, PM6‐Ir1, PM6‐Ir2.5, and PM6‐Ir5) are synthesized and characterized. It is demonstrated that the approach can rationally modify the molecular aggregations of polymer donors, effectively controlling the corresponding blend morphology and physical mechanisms, and finally improve the photovoltaic performance of the PM6‐Irx‐based PSCs. Among them, the best device based on PM6‐Ir1:Y6 (1:1.2, w/w) exhibits outstanding power conversion efficiencies (PCEs) of 17.24% tested at Wuhan University and 17.32% tested at Institute of Chemistry, Chinese Academy of Sciences as well as a certified PCE of 16.70%, which are much higher than that of the control device based on the PM6‐Ir0:Y6 blend (15.39%). This work affords an effective approach for further break through the reported champion PCE of the binary PSCs.     

A rigorous experimental framework for detecting protein oligomerization using bioluminescence resonance energy transfer

Bioluminescence resonance energy transfer (BRET), which relies on nonradiative energy transfer between luciferase-coupled donors and GFP-coupled acceptors, is emerging as a useful tool for analyzing the quaternary structures of cell-surface molecules. Conventional BRET analyses are generally done at maximal expression levels and single acceptor/donor ratios. We show that under these conditions substantial energy transfer arises from random interactions within the membrane. The dependence of BRET efficiency on acceptor/donor ratio at fixed surface density, or expression level at a defined acceptor/donor ratio, can nevertheless be used to correctly distinguish between well-characterized monomeric and oligomeric proteins, including a very weak dimer. The pitfalls associated with the nonrigorous treatment of BRET data are illustrated for the case of G protein-coupled receptors (GPCRs) proposed to form homophilic and/or mixed oligomers on the basis of previous, conventional BRET experiments.     

Alkyl Chain Length Effects of Polymer Donors on the Morphology and Device Performance of Polymer Solar Cells with Different Acceptors

The development of nonfullerene acceptors has brought polymer solar cells into a new era. Maximizing the performance of nonfullerene solar cells needs appropriate polymer donors that match with the acceptors in both electrical and morphological properties. So far, the design rationales for polymer donors are mainly borrowed from fullerene‐based solar cells, which are not necessarily applicable to nonfullerene solar cells. In this work, the influence of side chain length of polymer donors based on a set of random terpolymers PTAZ‐TPD10‐Cn on the device performance of polymer solar cells is investigated with three different acceptor materials, i.e., a fullerene acceptor [70]PCBM, a polymer acceptor N2200, and a fused‐ring molecular acceptor ITIC. Shortening the side chains of polymer donors improves the device performance of [70]PCBM‐based devices, but deteriorates the N2200‐ and ITIC‐based devices. Morphology studies unveil that the miscibility between donor and acceptor in blend films depends on the side chain length of polymer donors. Upon shortening the side chains of the polymer donors, the miscibility between the donor and acceptor increases for the [70]PCBM‐based blends, but decreases for the N2200‐ and ITIC‐based blends. These findings provide new guidelines for the development of polymer donors to match with emerging nonfullerene acceptors.     

Medium Bandgap Polymer Donor Based on Bi(trialkylsilylthienyl‐benzo[1,2‐b:4,5‐b′]‐difuran) for High Performance Nonfullerene Polymer Solar Cells

A new 2D‐conjugated medium bandgap donor–acceptor copolymer, J81 , based on benzodifuran with trialkylsilyl thiophene side chains as donor unit and fluorobenzothiazole as acceptor, is synthesized and successfully used in nonfullerene polymer solar cells (PSCs) with low bandgap n‐type organic semiconductor (n‐OS) 3,9‐bis(2‐methylene‐ (3‐(1,1‐dicyanomethylene)‐indanone)‐5,5,11,11‐tetrakis(4‐ hexylphenyl)‐dithieno[2,3‐d:2′,3′‐d′]‐s‐indaceno[1,2‐b:5,6‐b′]‐ dithiophene (ITIC) and m ‐ITIC as acceptor. J81 possesses a lower‐lying highest occupied molecular orbital (HOMO) energy level of ?5.43 eV and medium bandgap of 1.93 eV with complementary absorption in the visible–near infrared region with the n‐OS acceptor. The PSCs based on J81 :ITIC and J81 :m ‐ITIC yield high power conversion efficiency of 10.60% and 11.05%, respectively, with high V _oc of 0.95–0.96 V benefit from the lower‐lying HOMO energy level of J81 donor. The work indicates that J81 is another promising polymer donor for the nonfullerene PSCs.     

Structure Evolution of Oligomer Fused‐Ring Electron Acceptors toward High Efficiency of As‐Cast Polymer Solar Cells

The structure evolution of oligomer fused‐ring electron acceptors (FREAs) toward high efficiency of as‐cast polymer solar cells (PSCs) is reported. First, a series of FREAs (IC‐(1‐3)IDT‐IC) based on indacenodithiophene (IDT) oligomers as cores are designed and synthesized, effects of IDT number (1–3) on their basic optical and electronic properties are investigated, and more importantly, the relationship between device performance of as‐cast PSCs and donor(D)/acceptor(A) matching (absorption, energy level, morphology, and charge transport) of IC‐(1‐3)IDT‐IC acceptors and two representative polymer donors, PTB7‐Th and PDBT‐T1 is surveyed. Then, the most promising D/A system (PDBT‐T1/IC‐1IDT‐IC) with the best D/A harmony among the six D/A combinations, which yields a power conversion efficiency (PCE) of 7.39%, is found. Finally, changing the side‐chains in IC‐1IDT‐IC from alkylphenyl to alkyl enhances the PCE from 7.39% to 9.20%.     

Influence of Donor Polymer on the Molecular Ordering of Small Molecular Acceptors in Nonfullerene Polymer Solar Cells

Nonfullerene polymer solar cells (PSCs) based on polymer donors and nonfullerene small molecular acceptors (SMAs) have recently attracted considerable attention. Although much of the progress is driven by the development of novel SMAs, the donor polymer also plays an important role in achieving efficient nonfullerene PSCs. However, it is far from clear how the polymer donor choice influences the morphology and performance of the SMAs and the nonfullerene blends. In addition, it is challenging to carry out quantitative analysis of the morphology of polymer:SMA blends, due to the low material contrast and overlapping scattering features of the π–π stacking between the two organic components. Here, a series of nonfullerene blends is studied based on ITIC‐Th blended with five different donor polymers. Through quantitative morphology analysis, the (010) coherence length of the SMA is characterized and a positive correlation between the coherence length of the SMA and the device fill factor (FF) is established. The study reveals that the donor polymer can significantly change the molecular ordering of the SMA and thus improve the electron mobility and domain purity of the blend, which has an overall positive effect that leads to the enhanced device FF for nonfullerene PSCs.     

The Importance of Pendant Groups on Triphenylamine‐Based Hole Transport Materials for Obtaining Perovskite Solar Cells with over 20% Efficiency

Tremendous progress has recently been achieved in the field of perovskite solar cells (PSCs) as evidenced by impressive power conversion efficiencies (PCEs); but the high PCEs of >20% in PSCs has so far been mostly achieved by using the hole transport material (HTM) spiro‐OMeTAD; however, the relatively low conductivity and high cost of spiro‐OMeTAD significantly limit its potential use in large‐scale applications. In this work, two new organic molecules with spiro[fluorene‐9,9′‐xanthene] (SFX)‐based pendant groups, X26 and X36, have been developed as HTMs. Both X26 and X36 present facile syntheses with high yields. It is found that the introduced SFX pendant groups in triphenylamine‐based molecules show significant influence on the conductivity, energy levels, and thin‐film surface morphology. The use of X26 as HTM in PSCs yields a remarkable PCE of 20.2%. In addition, the X26‐based devices show impressive stability maintaining a high PCE of 18.8% after 5 months of aging in controlled (20%) humidity in the dark. We believe that X26 with high device PCEs of >20% and simple synthesis show a great promise for future application in PSCs, and that it represents a useful design platform for designing new charge transport materials for optoelectronic applications.     

Thermally Stable All‐Polymer Solar Cells with High Tolerance on Blend Ratios

Tuning the blend composition is an essential step to optimize the power conversion efficiency (PCE) of organic bulk heterojunction (BHJ) solar cells. PCEs from devices of unoptimized donor:acceptor (D:A) weight ratio are generally significantly lower than optimized devices. Here, two high‐performance organic nonfullerene BHJ blends PBDB‐T:ITIC and PBDB‐T:N2200 are adopted to investigate the effect of blend ratio on device performance. It is found that the PCEs of polymer‐polymer (PBDB‐T:N2200) blend are more tolerant to composition changes, relative to polymer‐molecule (PBDB‐T:ITIC) devices. In both systems, short‐circuit current density (J_sc) is tracked closely with PCE, indicating that exciton dissociation and transport strongly influence PCEs. With dilute acceptor concentrations, polymer‐polymer blends maintain high electron mobility relative to the polymer‐molecule blends, which explains the dramatic difference in PCEs between them as a function of D:A blend ratio. In addition, polymer‐polymer solar cells, especially at high D:A blend ratio, are stable (less than 5% relative loss) over 70 d under continuous heating at 80 °C in a glovebox without encapsulation. This work demonstrates that all‐polymer solar cells show advantage in operational lifetime under thermal stress and blend‐ratio resilience, which indicates their high potential for designing of stable and scalable solar cells.     

A Halogenation Strategy for over 12% Efficiency Nonfullerene Organic Solar Cells

Three acceptor–donor–acceptor type nonfullerene acceptors (NFAs), namely, F–F, F–Cl, and F–Br, are designed and synthesized through a halogenation strategy on one successful nonfullerene acceptor FDICTF (F–H). The three molecules show red‐shifted absorptions, increased crystallinities, and higher charge mobilities compared with the F–H. After blending with donor polymer PBDB‐T, the F–F‐, F–Cl‐, and F–Br‐based devices exhibit power conversion efficiencies (PCEs) of 10.85%, 11.47%, and 12.05%, respectively, which are higher than that of F–H with PCE of 9.59%. These results indicate that manipulating the absorption range, crystallinity and mobilities of NFAs by introducing different halogen atoms is an effective way to achieve high photovoltaic performance, which will offer valuable insight for the designing of high‐efficiency organic solar cells.