Organic solar cells based on narrow bandgap small-molecule acceptors(SMAs)with highly crystalline characteristics have attracted great attentions for their superiority in obtaining high photovoltaic efficiency.Employi...Organic solar cells based on narrow bandgap small-molecule acceptors(SMAs)with highly crystalline characteristics have attracted great attentions for their superiority in obtaining high photovoltaic efficiency.Employing highly crystalline SMAs to enhance power conversion efficiencies(PCEs)by regulating and controlling morphology and compatibility of donor and acceptor materials has turned out to be an effective approach.In this study,we synthesized three different crystalline SMAs by using fluorine substitution on alkoxyphenyl conjugated side chains to modulate the relationship of crystallinity and morphologies,namely ZY1(zero F atoms),ZY2(two F atoms),and ZY3(four F atoms).The three SMAs show the broad absorption edges and similar frontier orbital energy levels,generating the analogical(over 0.9 V)open circuit voltage(VOC)of the polymer solar cells(PSCs).As a result,the PM6:ZY2-based PSCs yield a PCE of 10.81%with a VOC of 0.95 V,a short-circuit current density(JSC)of 16.154 mA cm^(-2),and a fill factor(FF)of 0.71,which is higher than that of 9.17%(PM6:ZY1)and 6.37%(PM6:ZY3).And the PCE(17.23%)of the PM6:Y6:ZY2 based ternary PSCs is also higher than that of 16.32%PM6:Y6 based binary device.Obviously,the results demonstrate that adding fluorine atoms on the conjugated side chains to construct high crystalline materials is a positive strategy to effectively increase the efficiencies of binary and ternary PSCs.展开更多
In this study,wide bandgap(WBG)two-dimensional(2D)copolymer donors(DZ1,DZ2,and DZ3)based on benzodithiophene(BDT)on alkoxyphenyl conjugated side chains without and with different amounts of chlorine atoms and difluoro...In this study,wide bandgap(WBG)two-dimensional(2D)copolymer donors(DZ1,DZ2,and DZ3)based on benzodithiophene(BDT)on alkoxyphenyl conjugated side chains without and with different amounts of chlorine atoms and difluorobenzotriazole(FBTZ)are designed and synthesized successfully for efficient non-fullerene polymer solar cells(PSCs).Three polymer donors DZ1,DZ2,and DZ3 display similar absorption spectra at 300-700 nm range with optional band-gap(Egopt)of 1.84,1.92,and 1.97 eV,respectively.Compared with reported DZ1 without chlorine substitution,it is found that introducing chlorine atoms into the meta-position of the alkoxyphenyl group affords polymer possessing a deeper the highest occupied molecular orbital(HOMO)energy level,which can increase open circuit voltage(Voc)of PSCs,as well as improve hole mobility.Non-fullerene bulk heterojunction PSCs based on DZ2:MelC demonstrate a relatively high power conversion efficiency(PCE)of 10.22%with a Voc of 0.88 V,a short-circuit current density(Jsc)of 17.62 mA/cm^2,and a fill factor(FF)of 68%,compared with PSCs based on DZ1:MelC(a PCE of 8.26%)and DZ3:MelC(a PCE of 6.28%).The results imply that adjusting chlorine atom amount on alkoxyphenyl side chains based on BDT polymer donors is a promising approach of synthesizing electron-rich building block for high performance of PSCs.展开更多
The recently reported efficient polymerized small-molecule acceptors(PSMAs)usually adopt a regioregular backbone by polymerizing small-molecule acceptors precursors with a low-reactivity 5-brominated 3-(dicyanomethyli...The recently reported efficient polymerized small-molecule acceptors(PSMAs)usually adopt a regioregular backbone by polymerizing small-molecule acceptors precursors with a low-reactivity 5-brominated 3-(dicyanomethylidene)indan-1-one(IC)end group or its derivatives,leading to low molecular weight,and thus reduce active layer mechanical properties.Herein,a series of newly designed chlorinated PSMAs originating from isomeric IC end groups are developed by adjusting chlorinated positions and copolymerized sites on end groups to achieve high molecular weight,favorable intermolecular interaction,and improved physicochemical properties.Compared with regioregular PY2Se-Cl-o and PY2Se-Cl-m,regiorandom PY2Se-Cl-ran has a similar absorption profile,moderate lowest unoccupied molecular orbital level,and favorable intermolecular packing and crystallization properties.Moreover,the binary PM6:PY2Se-Cl-ran blend achieves better ductility with a crack-onset strain of 17.5% and improved power conversion efficiency(PCE)of 16.23% in all-polymer solar cells(all-PSCs)due to the higher molecular weight of PY2Se-Cl-ran and optimized blend morphology,while the ternary PM6:J71:PY2Se-Cl-ran blend offers an impressive PCE approaching 17% and excellent device stability,which are all crucial for potential practical applications of all-PSCs in wearable electronics.To date,the efficiency of 16.86% is the highest value reported for the regiorandom PSMAs-based all-PSCs and is also one of the best values reported for the all-PSCs.Our work provides a new perspective to develop efficient all-PSCs,with all high active layer ductility,impressive PCE,and excellent device stability,towards practical applications.展开更多
Most of the recent organic solar cells(OSCs)with top-of-the-line efficiencies are processed from organic solvents with a high vapor pressure such as CF in nitrogen-filled glovebox,which is not feasible for large-area ...Most of the recent organic solar cells(OSCs)with top-of-the-line efficiencies are processed from organic solvents with a high vapor pressure such as CF in nitrogen-filled glovebox,which is not feasible for large-area manufacturing.Herein,we cast active layers with both aromatic hydrocarbon solvents and halogenated solvents without any solvent additive or post-treatment,as well as interlayers with water and methanol in air(35%relative humidity)for efficient OSCs,except cathode electrode's evaporation is in vacuum.Compared to the PM6:Y6 system that is processed from CF,the PM6:BTP-ClBr2 system demonstrates good efficiency of 16.28%processed from CB and the device based on PM6:BTP-4Cl achieves 16.33%using TMB as its solvent for the active layer.These are among the highest efficiencies for CB-and TMB-processed binary OSCs to date.The molecular packing and phase separation length scales of each combination depend strongly on the solvent,and the overall morphology is the result of the interplay between solvent evaporation(kinetics)and materials miscibility(thermodynamics).Different solvents are required to realize the optimal morphology due to the different miscibility between the donor and acceptor.Finally,17.36%efficiency was achieved by incorporating PC71BM for TMB-processed devices.Our result provides insights into the effect of processing solvent and shows the potential of realizing high-performance OSCs in conditions relevant for industrial fabrication.展开更多
With plenty of popular and effective ternary organic solar cells(OSCs)construction strategies proposed and applied,its power conversion efficiencies(PCEs)have come to a new level of over 19%in single-junction devices....With plenty of popular and effective ternary organic solar cells(OSCs)construction strategies proposed and applied,its power conversion efficiencies(PCEs)have come to a new level of over 19%in single-junction devices.However,previous studies are heavily based in chloroform(CF)leaving behind substantial knowledge deficiencies in understanding the influence of solvent choice when introducing a third component.Herein,we present a case where a newly designed asymmetric small molecular acceptor using fluoro-methoxylated end-group modification strategy,named BTP-BO-3FO with enlarged bandgap,brings different morphological evolution and performance improvement effect on host system PM6:BTP-eC9,processed by CF and ortho-xylene(o-XY).With detailed analyses supported by a series of experiments,the best PCE of 19.24%for green solvent-processed OSCs is found to be a fruit of finely tuned crystalline ordering and general aggregation motif,which furthermore nourishes a favorable charge generation and recombination behavior.Likewise,over 19%PCE can be achieved by replacing spin-coating with blade coating for active layer deposition.This work focuses on understanding the commonly met yet frequently ignored issues when building ternary blends to demonstrate cutting-edge device performance,hence,will be instructive to other ternary OSC works in the future.展开更多
Organic solar cells(OSCs)have experienced remarkable performance progress up to 20%benchmark power conversion efficiency(PCE)in past years.Considering the<1%initial PCE obtained by OSC decades ago,the milestone of ...Organic solar cells(OSCs)have experienced remarkable performance progress up to 20%benchmark power conversion efficiency(PCE)in past years.Considering the<1%initial PCE obtained by OSC decades ago,the milestone of surpassing 20%efficiency is of great significance.Meanwhile,further performance promotion is urgently required for OsCs as other solution-processable photovoltaic technologies are also competitive.This review article aims to demonstrate a comprehensive summary of recent reports on OSCs with over 20%PCE,delving into key strategies including material innovations,multi-component system construction,deposition protocol optimization,solid/solvent additive engineering,as well as hole/electron transport layer development.In addition,this study identifies the next-stage scientific and technological issues that warrant greater attention.These issues are proposed to drive more prosperous research development,particularly in the field of flexible and wearable power suppliers.展开更多
Biaxially conjugated acceptors(BCAs) have emerged as a promising strategy for the design of high-performance organic solar cell materials,achieved through the incorporation of an additional conjugated core to enhance ...Biaxially conjugated acceptors(BCAs) have emerged as a promising strategy for the design of high-performance organic solar cell materials,achieved through the incorporation of an additional conjugated core to enhance intermolecular interactions.Herein,we develop three BCAs(designated T1,T2,and T3),differentiated by the cyano group numbers in their central core.It is observed that Cyano substitution strengthens intermolecular interactions,leading to increased crystal coherence lengths.Notably,the D18:T2 blend exhibits pronounced fringed-micelle structures—a first in BCAs—wherein micelles are substantially larger than fibers,resulting in superior morphological characteristics.Consequently,the D18:T2 device attains a power conversion efficiency(PCE) of 19.05%,outperforming that of devices based on T1 and T3 due to improved exciton diffusion and charge transport.An incremental enhancement to a PCE of 19.71% is realized by substituting the PEDOT:PSS layer with a selfassembled 2PACz monolayer.Additionally,the T2-based device sustains efficiencies exceeding 17.5% across a broad thickness range of 120–300 nm,demonstrating low sensitivity to film thickness variations.This study not only confirms the crucial role of cyano substitution in elevating the efficiency of BCAs,but also illustrates how such groups strengthen molecular interactions,thereby facilitating the formation of fringed-micelle structures that positively impact the device efficiency.展开更多
Power conversion efficiency(PCE)of single-junction polymer solar cells(PSCs)has made a remarkable breakthrough recently.Plenty of work was reported to achieve PCEs higher than 16%derived from the PM6:Y6 binary system....Power conversion efficiency(PCE)of single-junction polymer solar cells(PSCs)has made a remarkable breakthrough recently.Plenty of work was reported to achieve PCEs higher than 16%derived from the PM6:Y6 binary system.To further increase the PCEs of binary OSCs incorporating small molecular acceptor(SMA)Y6,we substituted PM6 with PM7 due to the deeper highest occupied molecular orbital(HOMO)of PM7.Consequently,the PM7:Y6 has achieved PCEs as high as 17.0%by the hotcast method,due to the improved open-circuit voltage(VOC).Compared with PM6,the lower HOMO of PM7 increases the gap between ELUMO-donor and EHOMO-acceptor,which is proportional to VOC.This research provides a high PCE for single-junction binary PSCs,which is meaningful for device fabrication related to PM7 and commercialization of PSCs.展开更多
The emergence of the latest generation of small-molecule acceptor(SMA)materials,with Y6 as a typical example,accounts for the surge in device performance for organic solar cells(OSCs).This study proposes two new accep...The emergence of the latest generation of small-molecule acceptor(SMA)materials,with Y6 as a typical example,accounts for the surge in device performance for organic solar cells(OSCs).This study proposes two new acceptors named Y6-C2 and Y6-C3,from judicious alteration of alkyl-chains branching positions away from the Y6 backbone.Compared to the Y6,the Y6-C2 exhibits similar optical and electrochemical properties,but better molecular packing and enhanced crystallinity.In contrast,the Y6-C3 shows a significant blue-shift absorption in the solid state relative to the Y6 and Y6-C2.The as-cast PM6:Y6-C2-based OSC yields a higher power conversion efficiency(PCE)of 15.89%than those based on the Y6(15.24%)and Y6-C3(13.76%),representing the highest known value for as-cast nonfullerene OSCs.Prominently,the Y6-C2 displays a good compatibility with the PC71BM.Therefore,a ternary OSC device based on PM6:Y6-C2:PC71BM(1.0:1.0:0.2)was produced,and it exhibits an outstanding PCE of 17.06%and an impressive fill factor(FF)of 0.772.Our results improve understanding of the structureproperty relationship for state-of-the-art SMAs and demonstrate that modulating the structure of SMAs via fine-tuning of alkylchains branching positions is an effective method to enhance their performance.展开更多
The non-fully conjugated polymer as a new class of acceptor materials has shown some advantages over its small molecular counterpart when used in photoactive layers for all-polymer solar cells(all-PSCs),despite a low ...The non-fully conjugated polymer as a new class of acceptor materials has shown some advantages over its small molecular counterpart when used in photoactive layers for all-polymer solar cells(all-PSCs),despite a low power conversion efficiency(PCE)caused by its narrow absorption spectra.Herein,a novel non-fully conjugated polymer acceptor PFY-2TS with a low bandgap of~1.40 eV was developed,via polymerizing a largeπ-fused small molecule acceptor(SMA)building block(namely YBO)with a non-conjugated thioalkyl linkage.Compared with its precursor YBO,PFY-2TS retains a similar low bandgap but a higher LUMO level.Moreover,compared with the structural analog of YBO-based fully conjugated polymer acceptor PFY-DTC,PFY-2TS shows a similar absorption spectrum and electron mobility,but significantly different molecular crystallinity and aggregation properties,which results in optimal blend morphology with a polymer donor PBDB-T and physical processes of the device in all-PSCs.As a result,PFY-2TS-based all-PSCs achieved a PCE of 12.31%with a small energy loss of 0.56 eV enabled by the reduced non-radiative energy loss(0.24 eV),which is better than that of 11.08%for the PFY-DTC-based ones.Our work clearly demonstrated that non-fully conjugated polymers as a new class of acceptor materials are very promising for the development of high-performance all-PSCs.展开更多
Two p-type small molecules BDTT-TR and TBFT-TR with benzo[1,2-b′:4,5-b′]dithiophene(BDT)and thieno[2,3-f]benzofuran(TBF)as central core units are synthesized and used as donors in all-small-molecule organic solar ce...Two p-type small molecules BDTT-TR and TBFT-TR with benzo[1,2-b′:4,5-b′]dithiophene(BDT)and thieno[2,3-f]benzofuran(TBF)as central core units are synthesized and used as donors in all-small-molecule organic solar cells(all-SMOSCs)with a narrow-bandgap small molecule Y6(2,2′-((2 Z,2′Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3’′:4’,5′]thieno[2′,3′:4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1 H-indene-2,1-diylidene))dimalononitrile)as the acceptor.In comparison to BDTT-TR with centrosymmetric BDT as the central unit,TBFT-TR with asymmetric TBF as the central unit shows red-shifted absorption,higher charge-carrier mobility and better charge pathway in blend films.The power conversion efficiency(PCE)of the all-SMOSCs based on TBFT-TR:Y6 reaches 14.03%with a higher short-circuit current density of 24.59 m A cm-2 and a higher fill factor of72.78%compared to the BDTT-TR:Y6 system.The PCE of 14.03%is among the top efficiencies of all-SMOSCs reported in the literature to date.展开更多
Considering the robust and stable nature of the active layers,advancing the power conversion efficiency(PCE)has long been the priority for all-polymer solar cells(all-PSCs).Despite the recent surge of PCE,the photovol...Considering the robust and stable nature of the active layers,advancing the power conversion efficiency(PCE)has long been the priority for all-polymer solar cells(all-PSCs).Despite the recent surge of PCE,the photovoltaic parameters of the stateof-the-art all-PSC still lag those of the polymer:small molecule-based devices.To compete with the counterparts,judicious modulation of the morphology and thus the device electrical properties are needed.It is difficult to improve all the parameters concurrently for the all-PSCs with advanced efficiency,and one increase is typically accompanied by the drop of the other(s).In this work,with the aids of the solvent additive(1-chloronaphthalene)and the n-type polymer additive(N2200),we can fine-tune the morphology of the active layer and demonstrate a 16.04%efficient all-PSC based on the PM6:PY-IT active layer.The grazing incidence wideangle X-ray scattering measurements show that the shape of the crystallites can be altered,and the reshaped crystallites lead to enhanced and more balanced charge transport,reduced recombination,and suppressed energy loss,which lead to concurrently improved and device efficiency and stability.展开更多
One of the most appealing material systems for solar energy conversion is allpolymer blend.Presently,the three key merits(power conversion efficiency,operation stability and mechanical robustness)exhibited a trade-off...One of the most appealing material systems for solar energy conversion is allpolymer blend.Presently,the three key merits(power conversion efficiency,operation stability and mechanical robustness)exhibited a trade-off in a particular all-polymer blend system,which greatly limit its commercial application.Diverting the classic ternary tactic of organic solar cells based on polymer,nonfullerene small molecule and fullerene,herein we demonstrate that the three merits of a benchmark all-polymer blend PM6:PY-IT can be simultaneously maximized via the introduction of a polymerized fullerene derivative PPCBMB.Importantly,the addition of the vip component promoted the power conversion efficiency of PM6:PY-IT blend from 16.59%to 18.04%.Meanwhile,the device stability and film ductility are also improved due to the addition of this polymerized fullerene material.Morphology and device physics analyses reveal that optimal ternary system contains well-maintained molecular packing and crystallinity,being beneficial to keeping favorable charge transport and the reduced domain size contributed to charge generation and ductility improvement.Furthermore,the ternary photovoltaic blend was successfully used as photocatalysts,and an excellent heavy metal removal from water was demonstrated.This study showcases the multi-functions of all-polymer blends via the use of polymerized fullerenes.展开更多
Fine-tuning of the electron-deficient unit in A-DA1D-A typed small-molecule acceptors (SMAs) plays a crucial role in developing efficient SMAs for organic solar cells (OSCs).Here,we developed a SMA based on benzo[4,5]...Fine-tuning of the electron-deficient unit in A-DA1D-A typed small-molecule acceptors (SMAs) plays a crucial role in developing efficient SMAs for organic solar cells (OSCs).Here,we developed a SMA based on benzo[4,5]thieno[2,3-b]quinoxaline,designated as QW1,as well as three SMAs based on 1-methylindoline-2,3-dione,identified as QW2,QW3,and QW4.Compared with QW2,QW1 displays slightly blue-shifted absorption spectra and a lower LUMO energy level due to the stronger electron-withdrawing capability of BTQx in contrast to MDO.On the other hand,the introduction of a bromine atom in QW3 and QW4 causes a blue shift in absorption and a reduction in the LUMO energy level compared to QW2.Density functional theory analysis reveals that QW1 exhibits the best molecular planarity,which endows QW1 with larger electron mobility and tighter molecular stacking.Consequently,PM6:QW1 device affords a better efficiency of 15.63% than those of the devices based on QW2 (14.25%),QW3 (13.21%) and QW4 (15.03%).Moreover,the QW4-based device yields the highest open-circuit voltage of 0.933 V,and the PM6:L8-BO:QW4 ternary device realizes a PCE of 19.03%.Overall,our work demonstrates that regulation of electron-deficient central units is an effective strategy to improve the photovoltaic performance of the resulting A-DA1D-A SMAs.展开更多
State-of-the-art organic solar cells(OSCs)often require the use of high-boiling point additive or post-treatment such as temperature annealing and solvent vapor annealing to achieve the best efficiency.However,additiv...State-of-the-art organic solar cells(OSCs)often require the use of high-boiling point additive or post-treatment such as temperature annealing and solvent vapor annealing to achieve the best efficiency.However,additives are not desirable in largescale industrial printing process,while post-treatment also increases the production cost.In this article,we report highly efficient ternary OSCs based on PM6:BTP-Cl Br1:BTP-2O-4Cl-C12(weight ratio=1:1:0.2),with 16.68%power conversion efficiency(PCE)for as-cast device,relatively close to its annealed counterpart(17.19%).Apart from obvious energy tuning effect and complementary absorption spectra,the improved PCE of ternary device is mainly attributed to improved morphological properties including the more favorable materials miscibility,crystallinity,domain size and vertical phase separation,which endorse suppressed recombination.The result of this work provides understanding and guidance for high-performance as-cast OSCs through the ternary strategy.展开更多
基金the National Natural Science Foundation of China(Nos.51763017,21602150).
文摘Organic solar cells based on narrow bandgap small-molecule acceptors(SMAs)with highly crystalline characteristics have attracted great attentions for their superiority in obtaining high photovoltaic efficiency.Employing highly crystalline SMAs to enhance power conversion efficiencies(PCEs)by regulating and controlling morphology and compatibility of donor and acceptor materials has turned out to be an effective approach.In this study,we synthesized three different crystalline SMAs by using fluorine substitution on alkoxyphenyl conjugated side chains to modulate the relationship of crystallinity and morphologies,namely ZY1(zero F atoms),ZY2(two F atoms),and ZY3(four F atoms).The three SMAs show the broad absorption edges and similar frontier orbital energy levels,generating the analogical(over 0.9 V)open circuit voltage(VOC)of the polymer solar cells(PSCs).As a result,the PM6:ZY2-based PSCs yield a PCE of 10.81%with a VOC of 0.95 V,a short-circuit current density(JSC)of 16.154 mA cm^(-2),and a fill factor(FF)of 0.71,which is higher than that of 9.17%(PM6:ZY1)and 6.37%(PM6:ZY3).And the PCE(17.23%)of the PM6:Y6:ZY2 based ternary PSCs is also higher than that of 16.32%PM6:Y6 based binary device.Obviously,the results demonstrate that adding fluorine atoms on the conjugated side chains to construct high crystalline materials is a positive strategy to effectively increase the efficiencies of binary and ternary PSCs.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51763017,21602150,51425304,51863012,21861025,51833004)the Shen Zhen Technology and Innovation Commission(Nos.JCYJ20170413173814007,JCYJ20170818113905024)+4 种基金the Hong Kong Research Grants Council(Research Impact Fund R6021-18,Nos.16305915,16322416,606012,16303917)Hong Kong Innovation and Technology Commission for the support through projects ITC-CNERC14SC01 and ITS/471/18,the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP)(No.2018R1A2A1A05077194)Wearable Platform Materials Technology Center(WMCNo.2016R1A5A1009926)funded by the National Research Foundation of Korea(NRF)Grant by the Korean Government(MSIT)the Research Project Funded by Ulsan City(No.1.200042)of UNIST(Ulsan National Institute of Science&Technology).
文摘In this study,wide bandgap(WBG)two-dimensional(2D)copolymer donors(DZ1,DZ2,and DZ3)based on benzodithiophene(BDT)on alkoxyphenyl conjugated side chains without and with different amounts of chlorine atoms and difluorobenzotriazole(FBTZ)are designed and synthesized successfully for efficient non-fullerene polymer solar cells(PSCs).Three polymer donors DZ1,DZ2,and DZ3 display similar absorption spectra at 300-700 nm range with optional band-gap(Egopt)of 1.84,1.92,and 1.97 eV,respectively.Compared with reported DZ1 without chlorine substitution,it is found that introducing chlorine atoms into the meta-position of the alkoxyphenyl group affords polymer possessing a deeper the highest occupied molecular orbital(HOMO)energy level,which can increase open circuit voltage(Voc)of PSCs,as well as improve hole mobility.Non-fullerene bulk heterojunction PSCs based on DZ2:MelC demonstrate a relatively high power conversion efficiency(PCE)of 10.22%with a Voc of 0.88 V,a short-circuit current density(Jsc)of 17.62 mA/cm^2,and a fill factor(FF)of 68%,compared with PSCs based on DZ1:MelC(a PCE of 8.26%)and DZ3:MelC(a PCE of 6.28%).The results imply that adjusting chlorine atom amount on alkoxyphenyl side chains based on BDT polymer donors is a promising approach of synthesizing electron-rich building block for high performance of PSCs.
基金National Natural Science Foundation of China,Grant/Award Numbers:21704082,21875182,22005121Key Scientific and Technological Innovation Team Project of Shaanxi Province,Grant/Award Number:2020TD‐002111 project 2.0,Grant/Award Number:BP2018008。
文摘The recently reported efficient polymerized small-molecule acceptors(PSMAs)usually adopt a regioregular backbone by polymerizing small-molecule acceptors precursors with a low-reactivity 5-brominated 3-(dicyanomethylidene)indan-1-one(IC)end group or its derivatives,leading to low molecular weight,and thus reduce active layer mechanical properties.Herein,a series of newly designed chlorinated PSMAs originating from isomeric IC end groups are developed by adjusting chlorinated positions and copolymerized sites on end groups to achieve high molecular weight,favorable intermolecular interaction,and improved physicochemical properties.Compared with regioregular PY2Se-Cl-o and PY2Se-Cl-m,regiorandom PY2Se-Cl-ran has a similar absorption profile,moderate lowest unoccupied molecular orbital level,and favorable intermolecular packing and crystallization properties.Moreover,the binary PM6:PY2Se-Cl-ran blend achieves better ductility with a crack-onset strain of 17.5% and improved power conversion efficiency(PCE)of 16.23% in all-polymer solar cells(all-PSCs)due to the higher molecular weight of PY2Se-Cl-ran and optimized blend morphology,while the ternary PM6:J71:PY2Se-Cl-ran blend offers an impressive PCE approaching 17% and excellent device stability,which are all crucial for potential practical applications of all-PSCs in wearable electronics.To date,the efficiency of 16.86% is the highest value reported for the regiorandom PSMAs-based all-PSCs and is also one of the best values reported for the all-PSCs.Our work provides a new perspective to develop efficient all-PSCs,with all high active layer ductility,impressive PCE,and excellent device stability,towards practical applications.
基金financial support from National Natural Science Foundation of China 21927811support from the National Key Research and Development Program of China(No.2019YFA0705900)funded by MOST+7 种基金the Basic and Applied Basic Research Major Program of Guangdong Province(No.2019B030302007)Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials(project number 2019B121205002)the Shen Zhen Technology and Innovation Commission(project number JCYJ20170413173814007,JCYJ20170818113905024)the Hong Kong Research Grants Council(Research Impact Fund R6021-18,collaborative research fund C6023-19G,project numbers 16309218,16310019,and 16303917)Hong Kong Innovation and Technology Commission for the support through projects ITC-CNERC14SC01 and ITS/471/18National Natural Science Foundation of China(NSFC,No.91433202)support from Natural Science Foundation of Top Talent of SZTU(grant number:20200205)support from Hong Kong Ph D Fel owship Scheme PF17-03929。
文摘Most of the recent organic solar cells(OSCs)with top-of-the-line efficiencies are processed from organic solvents with a high vapor pressure such as CF in nitrogen-filled glovebox,which is not feasible for large-area manufacturing.Herein,we cast active layers with both aromatic hydrocarbon solvents and halogenated solvents without any solvent additive or post-treatment,as well as interlayers with water and methanol in air(35%relative humidity)for efficient OSCs,except cathode electrode's evaporation is in vacuum.Compared to the PM6:Y6 system that is processed from CF,the PM6:BTP-ClBr2 system demonstrates good efficiency of 16.28%processed from CB and the device based on PM6:BTP-4Cl achieves 16.33%using TMB as its solvent for the active layer.These are among the highest efficiencies for CB-and TMB-processed binary OSCs to date.The molecular packing and phase separation length scales of each combination depend strongly on the solvent,and the overall morphology is the result of the interplay between solvent evaporation(kinetics)and materials miscibility(thermodynamics).Different solvents are required to realize the optimal morphology due to the different miscibility between the donor and acceptor.Finally,17.36%efficiency was achieved by incorporating PC71BM for TMB-processed devices.Our result provides insights into the effect of processing solvent and shows the potential of realizing high-performance OSCs in conditions relevant for industrial fabrication.
基金R.Ma thanks the support from PolyU Distinguished Postdoc Fellowship(1-YW4C)Z.Luo thanks the National Natural Science Foundation of China(NSFC,No.22309119)+7 种基金J.Wu thanks the Guangdong government and the Guangzhou government for funding(2021QN02C110)the Guangzhou Municipal Science and Technology Project(No.2023A03J0097 and 2023A03J0003)H.Yan appreciates the support from the National Key Research and Development Program of China(No.2019YFA0705900)funded by MOST,the Basic and Applied Research Major Program of Guangdong Province(No.2019B030302007)the Shen Zhen Technology and Innovation Commission through(Shenzhen Fundamental Research Program,JCYJ20200109140801751)the Hong Kong Research Grants Council(research fellow scheme RFS2021-6S05,RIF project R6021-18,CRF project C6023‐19G,GRF project 16310019,16310020,16309221,and 16309822)Hong Kong Innovation and Technology Commission(ITC‐CNERC14SC01)Foshan‐HKUST(Project NO.FSUST19‐CAT0202)Zhongshan Municipal Bureau of Science and Technology(NO.ZSST20SC02)and Tencent Xplorer Prize。
文摘With plenty of popular and effective ternary organic solar cells(OSCs)construction strategies proposed and applied,its power conversion efficiencies(PCEs)have come to a new level of over 19%in single-junction devices.However,previous studies are heavily based in chloroform(CF)leaving behind substantial knowledge deficiencies in understanding the influence of solvent choice when introducing a third component.Herein,we present a case where a newly designed asymmetric small molecular acceptor using fluoro-methoxylated end-group modification strategy,named BTP-BO-3FO with enlarged bandgap,brings different morphological evolution and performance improvement effect on host system PM6:BTP-eC9,processed by CF and ortho-xylene(o-XY).With detailed analyses supported by a series of experiments,the best PCE of 19.24%for green solvent-processed OSCs is found to be a fruit of finely tuned crystalline ordering and general aggregation motif,which furthermore nourishes a favorable charge generation and recombination behavior.Likewise,over 19%PCE can be achieved by replacing spin-coating with blade coating for active layer deposition.This work focuses on understanding the commonly met yet frequently ignored issues when building ternary blends to demonstrate cutting-edge device performance,hence,will be instructive to other ternary OSC works in the future.
基金the National Natural Science Foundation of China(52422313 and 52173172)the PolyU Distinguished Postdoctoral Fellowship(1-YW4C)+4 种基金the National Natural Science Foundation of China(22475133,22309119,and 52303226)financially supported by the National Natural Science Foundation of China(52403239)the Sichuan Science and Technology Program(2023YFH0085 and 2023YFH0087)the National Key Laboratory of Advanced Polymer Materials(sklpme 2024-2-15)the Technology Development Program of Jilin Province(YDZJ202201ZYTS640)。
文摘Organic solar cells(OSCs)have experienced remarkable performance progress up to 20%benchmark power conversion efficiency(PCE)in past years.Considering the<1%initial PCE obtained by OSC decades ago,the milestone of surpassing 20%efficiency is of great significance.Meanwhile,further performance promotion is urgently required for OsCs as other solution-processable photovoltaic technologies are also competitive.This review article aims to demonstrate a comprehensive summary of recent reports on OSCs with over 20%PCE,delving into key strategies including material innovations,multi-component system construction,deposition protocol optimization,solid/solvent additive engineering,as well as hole/electron transport layer development.In addition,this study identifies the next-stage scientific and technological issues that warrant greater attention.These issues are proposed to drive more prosperous research development,particularly in the field of flexible and wearable power suppliers.
基金the support of the National Natural Science Foundation of China (NSFC)(22475133 and 22309119)the Shenzhen Science and Technology Program (20231120182602001 and ZDSYS20210623091813040)+2 种基金the Shenzhen University 2035 Program for Excellent Research (2024C007)the support of the Shenzhen Science and Technology Program (JCYJ2024081311330-6008)the support of the Guangdong Basic and Applied Basic Research Foundation (2023A1515110160)。
文摘Biaxially conjugated acceptors(BCAs) have emerged as a promising strategy for the design of high-performance organic solar cell materials,achieved through the incorporation of an additional conjugated core to enhance intermolecular interactions.Herein,we develop three BCAs(designated T1,T2,and T3),differentiated by the cyano group numbers in their central core.It is observed that Cyano substitution strengthens intermolecular interactions,leading to increased crystal coherence lengths.Notably,the D18:T2 blend exhibits pronounced fringed-micelle structures—a first in BCAs—wherein micelles are substantially larger than fibers,resulting in superior morphological characteristics.Consequently,the D18:T2 device attains a power conversion efficiency(PCE) of 19.05%,outperforming that of devices based on T1 and T3 due to improved exciton diffusion and charge transport.An incremental enhancement to a PCE of 19.71% is realized by substituting the PEDOT:PSS layer with a selfassembled 2PACz monolayer.Additionally,the T2-based device sustains efficiencies exceeding 17.5% across a broad thickness range of 120–300 nm,demonstrating low sensitivity to film thickness variations.This study not only confirms the crucial role of cyano substitution in elevating the efficiency of BCAs,but also illustrates how such groups strengthen molecular interactions,thereby facilitating the formation of fringed-micelle structures that positively impact the device efficiency.
基金supported by Shen Zhen Technology and Innovation Commission(JCYJ20170413173814007,JCYJ20170818113905024)Hong Kong Research Grants Council(Research Impact Fund R6021-18,16305915,16322416,606012,16303917)+2 种基金Hong Kong Innovation and Technology Commission(ITCCNERC14SC01,ITS/471/18)supported by National Natural Science Foundation of China(51573120,51973146,91633301)Collaborative Innovation Center of Suzhou Nano Science&Technology,and the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Power conversion efficiency(PCE)of single-junction polymer solar cells(PSCs)has made a remarkable breakthrough recently.Plenty of work was reported to achieve PCEs higher than 16%derived from the PM6:Y6 binary system.To further increase the PCEs of binary OSCs incorporating small molecular acceptor(SMA)Y6,we substituted PM6 with PM7 due to the deeper highest occupied molecular orbital(HOMO)of PM7.Consequently,the PM7:Y6 has achieved PCEs as high as 17.0%by the hotcast method,due to the improved open-circuit voltage(VOC).Compared with PM6,the lower HOMO of PM7 increases the gap between ELUMO-donor and EHOMO-acceptor,which is proportional to VOC.This research provides a high PCE for single-junction binary PSCs,which is meaningful for device fabrication related to PM7 and commercialization of PSCs.
基金supported by the National Natural Science Foundation of China(21572171,21702154,51773157,51873160)the National Basic Research Program of China(2013CB834805)+1 种基金Shenzhen Peacock Plan(KQTD2017033011-0107046)Beijing National Laboratory for Molecular Sciences(BNLMS201905).
文摘The emergence of the latest generation of small-molecule acceptor(SMA)materials,with Y6 as a typical example,accounts for the surge in device performance for organic solar cells(OSCs).This study proposes two new acceptors named Y6-C2 and Y6-C3,from judicious alteration of alkyl-chains branching positions away from the Y6 backbone.Compared to the Y6,the Y6-C2 exhibits similar optical and electrochemical properties,but better molecular packing and enhanced crystallinity.In contrast,the Y6-C3 shows a significant blue-shift absorption in the solid state relative to the Y6 and Y6-C2.The as-cast PM6:Y6-C2-based OSC yields a higher power conversion efficiency(PCE)of 15.89%than those based on the Y6(15.24%)and Y6-C3(13.76%),representing the highest known value for as-cast nonfullerene OSCs.Prominently,the Y6-C2 displays a good compatibility with the PC71BM.Therefore,a ternary OSC device based on PM6:Y6-C2:PC71BM(1.0:1.0:0.2)was produced,and it exhibits an outstanding PCE of 17.06%and an impressive fill factor(FF)of 0.772.Our results improve understanding of the structureproperty relationship for state-of-the-art SMAs and demonstrate that modulating the structure of SMAs via fine-tuning of alkylchains branching positions is an effective method to enhance their performance.
基金This work was supported by the Swedish Research Council(2015-04853,2016-06146,2019-04683)the Swedish Research Council Formas,the Knut and Alice Wallenberg Foundation(2017.0186,2016.0059)+5 种基金the Open Fund of the State Key Laboratory of Luminescent Materials and Devices(South China University of Technology,2020-skllmd-07)E.Moons thanks the Swedish Energy Council for financial support(project 48598-1)W.Su thanks the project funded by China Postdoctoral Science Foundation(2020M673054)Postdoctoral Fund of Jinan University,and the National Natural Science Foundation of China(22005121)L.Hou thanks the National Natural Science Foundation of China(61774077)Support from Sino-Danish Centre for Education and Research is fully acknowledged by D.Yu.Y.Li thanks the financial support from the Science and Technology Program of Shanxi Province(2019JQ-244).
文摘The non-fully conjugated polymer as a new class of acceptor materials has shown some advantages over its small molecular counterpart when used in photoactive layers for all-polymer solar cells(all-PSCs),despite a low power conversion efficiency(PCE)caused by its narrow absorption spectra.Herein,a novel non-fully conjugated polymer acceptor PFY-2TS with a low bandgap of~1.40 eV was developed,via polymerizing a largeπ-fused small molecule acceptor(SMA)building block(namely YBO)with a non-conjugated thioalkyl linkage.Compared with its precursor YBO,PFY-2TS retains a similar low bandgap but a higher LUMO level.Moreover,compared with the structural analog of YBO-based fully conjugated polymer acceptor PFY-DTC,PFY-2TS shows a similar absorption spectrum and electron mobility,but significantly different molecular crystallinity and aggregation properties,which results in optimal blend morphology with a polymer donor PBDB-T and physical processes of the device in all-PSCs.As a result,PFY-2TS-based all-PSCs achieved a PCE of 12.31%with a small energy loss of 0.56 eV enabled by the reduced non-radiative energy loss(0.24 eV),which is better than that of 11.08%for the PFY-DTC-based ones.Our work clearly demonstrated that non-fully conjugated polymers as a new class of acceptor materials are very promising for the development of high-performance all-PSCs.
基金the National Natural Science Foundation of China(21702154,51773157)the Fundamental Research Funds for the Central Universitiesthe Opening Project of Key Laboratory of Materials Processing and Mold and Beijing National Laboratory for Molecular Sciences(BNLMS201905)。
文摘Two p-type small molecules BDTT-TR and TBFT-TR with benzo[1,2-b′:4,5-b′]dithiophene(BDT)and thieno[2,3-f]benzofuran(TBF)as central core units are synthesized and used as donors in all-small-molecule organic solar cells(all-SMOSCs)with a narrow-bandgap small molecule Y6(2,2′-((2 Z,2′Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3’′:4’,5′]thieno[2′,3′:4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1 H-indene-2,1-diylidene))dimalononitrile)as the acceptor.In comparison to BDTT-TR with centrosymmetric BDT as the central unit,TBFT-TR with asymmetric TBF as the central unit shows red-shifted absorption,higher charge-carrier mobility and better charge pathway in blend films.The power conversion efficiency(PCE)of the all-SMOSCs based on TBFT-TR:Y6 reaches 14.03%with a higher short-circuit current density of 24.59 m A cm-2 and a higher fill factor of72.78%compared to the BDTT-TR:Y6 system.The PCE of 14.03%is among the top efficiencies of all-SMOSCs reported in the literature to date.
基金supported by the National Key Research and Development Program of China (number:2019YFA0705900)funded by MOSTthe Basic and Applied Basic Research Major Program of Guangdong Province (number:2019B030302007)+11 种基金Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials (project number:2019B121205002)the Shen Zhen Technology and Innovation Commission (project numbers:JCYJ20170413173814007 and JCYJ20170818113905024)the Hong Kong Research Grants Council (Research Impact Fund R6021-18,collaborative research fund C6023-19G,project numbers:16309218,16310019,and 16303917)Hong Kong Innovation and Technology Commission for the support through projects (ITC-CNERC14SC01 and ITS/471/18)National Natural Science Foundation of China (NSFC,number:91433202)support from National Natural Science Foundation of China 21927811support from the Swedish Research Council VR (2016-06146)the Swedish Research Council and The Knut and Alice Wallenberg Foundation (2017.0186,2016.0059)the support from Natural Science Foundation of Top Talent of SZTU (grant number:20200205)the support from Hong Kong PhD Fellowship Scheme PF17-03929the project funded by China Postdoctoral Science Foundation (2020M673054)Postdoctoral Fund of Jinan University,and National Natural Science Foundation of China (22005121).
文摘Considering the robust and stable nature of the active layers,advancing the power conversion efficiency(PCE)has long been the priority for all-polymer solar cells(all-PSCs).Despite the recent surge of PCE,the photovoltaic parameters of the stateof-the-art all-PSC still lag those of the polymer:small molecule-based devices.To compete with the counterparts,judicious modulation of the morphology and thus the device electrical properties are needed.It is difficult to improve all the parameters concurrently for the all-PSCs with advanced efficiency,and one increase is typically accompanied by the drop of the other(s).In this work,with the aids of the solvent additive(1-chloronaphthalene)and the n-type polymer additive(N2200),we can fine-tune the morphology of the active layer and demonstrate a 16.04%efficient all-PSC based on the PM6:PY-IT active layer.The grazing incidence wideangle X-ray scattering measurements show that the shape of the crystallites can be altered,and the reshaped crystallites lead to enhanced and more balanced charge transport,reduced recombination,and suppressed energy loss,which lead to concurrently improved and device efficiency and stability.
文摘One of the most appealing material systems for solar energy conversion is allpolymer blend.Presently,the three key merits(power conversion efficiency,operation stability and mechanical robustness)exhibited a trade-off in a particular all-polymer blend system,which greatly limit its commercial application.Diverting the classic ternary tactic of organic solar cells based on polymer,nonfullerene small molecule and fullerene,herein we demonstrate that the three merits of a benchmark all-polymer blend PM6:PY-IT can be simultaneously maximized via the introduction of a polymerized fullerene derivative PPCBMB.Importantly,the addition of the vip component promoted the power conversion efficiency of PM6:PY-IT blend from 16.59%to 18.04%.Meanwhile,the device stability and film ductility are also improved due to the addition of this polymerized fullerene material.Morphology and device physics analyses reveal that optimal ternary system contains well-maintained molecular packing and crystallinity,being beneficial to keeping favorable charge transport and the reduced domain size contributed to charge generation and ductility improvement.Furthermore,the ternary photovoltaic blend was successfully used as photocatalysts,and an excellent heavy metal removal from water was demonstrated.This study showcases the multi-functions of all-polymer blends via the use of polymerized fullerenes.
基金supported by the Shenzhen Science and Technology Program(ZDSYS20210623091813040,RCBS20221008093225021)the National Natural Science Foundation of China(NSFC,No.22309119)+2 种基金G.Li acknowledges the support from Research Grants Council of Hong Kong(Project Nos.15320216,15221320,C5037-18G,RGC Senior Research Fellowship Scheme(SRFS2223-5S01))the Hong Kong Polytechnic University(Sir Sze-yuen Chung Endowed Professorship Fund(8-8480)PolyU Distinguished postdoc Fellowship(1-YW4C,R.Ma),G-SAC5)。
文摘Fine-tuning of the electron-deficient unit in A-DA1D-A typed small-molecule acceptors (SMAs) plays a crucial role in developing efficient SMAs for organic solar cells (OSCs).Here,we developed a SMA based on benzo[4,5]thieno[2,3-b]quinoxaline,designated as QW1,as well as three SMAs based on 1-methylindoline-2,3-dione,identified as QW2,QW3,and QW4.Compared with QW2,QW1 displays slightly blue-shifted absorption spectra and a lower LUMO energy level due to the stronger electron-withdrawing capability of BTQx in contrast to MDO.On the other hand,the introduction of a bromine atom in QW3 and QW4 causes a blue shift in absorption and a reduction in the LUMO energy level compared to QW2.Density functional theory analysis reveals that QW1 exhibits the best molecular planarity,which endows QW1 with larger electron mobility and tighter molecular stacking.Consequently,PM6:QW1 device affords a better efficiency of 15.63% than those of the devices based on QW2 (14.25%),QW3 (13.21%) and QW4 (15.03%).Moreover,the QW4-based device yields the highest open-circuit voltage of 0.933 V,and the PM6:L8-BO:QW4 ternary device realizes a PCE of 19.03%.Overall,our work demonstrates that regulation of electron-deficient central units is an effective strategy to improve the photovoltaic performance of the resulting A-DA1D-A SMAs.
基金support by the National Key Research and Development Program of China(2019YFA0705900)funded by Minister of Science and Technologythe Basic and Applied Basic Research Major Program of Guangdong Province(2019B030302007)+9 种基金the Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials(2019B121205002)the Shen Zhen Technology and Innovation Commission(JCYJ20170413173814007,JCYJ20170818113905024)the Hong Kong Research Grants Council(Research Impact Fund R6021-18,collaborative research fund C6023-19G,project numbers,16309218,16310019,16303917)Hong Kong Innovation and Technology Commission(for the support through projects ITCCNERC14SC01 and ITS/471/18)the National Natural Science Foundation of China(NSFC,91433202)the support by the National Natural Science Foundation of China(NSFC,51773142,51973146)the Jiangsu Provincial Natural Science Foundation(BK20190099)the Collaborative Innovation Center of Suzhou Nano Science&Technology,the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe support by Hong Kong PhD Fellowship Scheme(PF17-03929)the support from Design and Manufacturing Services Facility(DMSF)and Materials Characterization and Preparation Facility(MCPF)of Hong Kong University of Science&Technology(HKUST)on characterizations。
文摘State-of-the-art organic solar cells(OSCs)often require the use of high-boiling point additive or post-treatment such as temperature annealing and solvent vapor annealing to achieve the best efficiency.However,additives are not desirable in largescale industrial printing process,while post-treatment also increases the production cost.In this article,we report highly efficient ternary OSCs based on PM6:BTP-Cl Br1:BTP-2O-4Cl-C12(weight ratio=1:1:0.2),with 16.68%power conversion efficiency(PCE)for as-cast device,relatively close to its annealed counterpart(17.19%).Apart from obvious energy tuning effect and complementary absorption spectra,the improved PCE of ternary device is mainly attributed to improved morphological properties including the more favorable materials miscibility,crystallinity,domain size and vertical phase separation,which endorse suppressed recombination.The result of this work provides understanding and guidance for high-performance as-cast OSCs through the ternary strategy.
