The integration of advanced diagnostic and therapeutic capabilities in oncology has given rise to phototheranostics,a field that combines the precision of imaging with the selectivity of light-activated treatments.Due...The integration of advanced diagnostic and therapeutic capabilities in oncology has given rise to phototheranostics,a field that combines the precision of imaging with the selectivity of light-activated treatments.Due to their pronounced near-infrared(NIR)absorption,tunable molecular structures,and commendable stability,organic photovoltaic non-fullerene acceptors(NFAs)represent a promising frontier in cancer management.Despite the great potential of NFAs in phototheranostics,there is currently a lack of systematic reviews in this field.This review provides a meticulous examination of the current state of NFAs in the field of phototheranostics,highlighting the strategic approaches to spectral red-shifting that enhance tissue penetration and therapeutic efficacy.It dissects the link between molecular architecture and performance across key therapeutic and diagnostic modalities,including photothermal therapy(PTT),photodynamic therapy(PDT),and fluorescence imaging(FLI).In addition,the review presents a concise analysis of the challenges and milestones in the clinical translation of NFAs,offering insights into the innovations required to overcome existing barriers.展开更多
Benzotriazole(BTA)-based A_(2)-A_1-D-A_1-A_(2)type wide-bandgap(WBG)non-fullerene acceptors(NFAs)have shown promising potential in indoor photovoltaic,and in-depth investigation of their structure-property relationshi...Benzotriazole(BTA)-based A_(2)-A_1-D-A_1-A_(2)type wide-bandgap(WBG)non-fullerene acceptors(NFAs)have shown promising potential in indoor photovoltaic,and in-depth investigation of their structure-property relationship is of great significance.Herein,we explored the chlorination effect of the side chain on the terminals.We introduced Cl atoms into the benzyl side chains in parent BTA5 to synthesize two NFAs,BTA5-Cl with mono-chlorinated benzyl groups and BTA5-2Cl containing bi-chlorinated benzyl groups.We chose D18-Cl with deep-energy levels and strong crystallinity to pair with these three acceptors,affording high photovoltage and photocurrent.With the stepwise chlorination,the open-circuit voltage(V_(OC))values decrease from 1.28,1.22,to 1.20 V,while the corresponding power conversion efficiencies(PCEs)improve from 5.07%,9.15%,to 10.96%.Compared with BTA5-based OSCs,introducing Cl atoms downshifts the energy levels and slightly increases the non-radiative energy loss(0.14<0.17<0.19 e V),resulting in a sequential decrease in VO C.However,more chlorine atom replacements produce more effective exciton dissociation,higher charge transfer,and balanced carrier mobility in the blend films,ultimately achieving better PCEs.This work indicates that chlorination of the benzyl group on the terminals can improve the device's performance,implying good application potential in indoor photovoltaics.展开更多
High-voltage lithium(Li)metal batteries(LMBs)face substantial challenges,including Li dendrite growth and instability in high-voltage cathodes such as LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM811),which impede their practic...High-voltage lithium(Li)metal batteries(LMBs)face substantial challenges,including Li dendrite growth and instability in high-voltage cathodes such as LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM811),which impede their practical applications and long-term stability.To address these challenges,tris(pentafluorophenyl)borane additive as an electron acceptor is introduced into an ethyl methyl carbonate/fluoroethylene carbonate-based electrolyte.This approach effectively engineers robust dual interfaces on the Li metal anode and the NCM811 cathode,thereby mitigating dendritic growth of Li and enhancing the stability of the cathode.This additive-driven strategy enables LMBs to operate at ultra-high voltages up to 4.7 V.Consequently,Li||Cu cells achieve a coulombic efficiency of 98.96%,and Li||Li symmetric cells extend their cycle life to an impressive 4000 h.Li||NCM811 full cells maintain a high capacity retention of 87.8%after 100 cycles at 4.7 V.Additionally,Li||LNMO full cells exhibit exceptional rate capability,delivering 132.2 mAh g^(-1)at 10 C and retaining 95.0%capacity after 250 cycles at 1 C and 5 V.As a result,NCM811||graphite pouch cells maintain a 93.4%capacity retention after 1100 cycles at 1 C.These findings underscore the efficacy of additive engineering in addressing Li dendrite formation and instability of cathode under high voltage,thereby paving the road for durable,high-performance LMBs.展开更多
The asymmetric molecular design strategy,with advantages in modulating the molecular dipole moment and intermolecular interactions and achieving more favorable molecular packing and orientation,has been an effective a...The asymmetric molecular design strategy,with advantages in modulating the molecular dipole moment and intermolecular interactions and achieving more favorable molecular packing and orientation,has been an effective approach for designing high-performance nonfullerene acceptors(NFAs).Herein,two asymmetric NFAs,Y-CN-2F and Y-CN-2Cl,were designed and synthesized by introducing a linear alkyl chain terminated with the 4-cyanobiphenyl group,a well-known mesogenic unit,at one of the inner pyrrole positions instead of the normal 2-butyloctyl branched alkyl chain.The difference between Y-CN-2F and Y-CN-2Cl is the terminated IC-groups,which was modified with F and Cl halogens,respectively.Both NFAs displayed strong absorption in the near-infrared to visible-light range,which is complementary to that of typical medium-bandgap donor polymers.After optimization with D18 donor in organic solar cells(OSCs),Y-CN-2F and Y-CN-2Cl provided comparable power conversion efficiencies(PCEs)of 15.33%and 15.88%.While the D18:Y-CN-2F based devices displayed higher fill factors(FFs),those based on D18:Y-CN-2Cl exhibited higher current densities and open-circuit voltages.The Y-CN-2Cl film showed longer light absorption than YCN-2F,which is beneficial for more light harvesting.Moreover,D18:Y-CN-2Cl displayed a lower fluorescence lifetime and faster carrier transfer processes,which could be attributed to its higher mobility.For the D18:Y-CN-2F blended film,a more pronounced fiber network structure and balanced carrier mobility were observed,which contributed to the higher FFs values.This work presents new efforts to develop more asymmetric NFAs with specific functional segments for efficient organic electronics.展开更多
Polymer acceptor configuration and aggregation behavior are critical in determining the photovoltaic performance of all-polymer solar cells(all-PSCs).Effectively manipulating polymer self-aggregation through structura...Polymer acceptor configuration and aggregation behavior are critical in determining the photovoltaic performance of all-polymer solar cells(all-PSCs).Effectively manipulating polymer self-aggregation through structural design to optimize the blend morphology remains challenging.Herein,we present a simple yet effective design strategy to modulate the aggregation behavior of the Y-series-based polymer acceptor PY-V-γby introducing a pendant-fluorinated Y-series acceptor(Y2F-ET)into the main-conjugated backbone.Two random copolymer acceptors(PY-EY-5 and PY-EY-20)were synthesized with varying molar fractions of Y2F-ET pendant monomers.Our findings revealed that both the solution-phase and solid-state aggregation behaviors were progressively suppressed as the Y2F-ET content increased.Compared to the highly self-aggregating PY-V-γ-based all-PSCs,the more amorphous PY-EY-5 enabled devices to achieve an increased device efficiency from 17.31%to 18.45%,which is attributed to the slightly smaller polymer phase-separation domain sizes and reduced molecular aggregation in the PM6:PY-EY-5 blend.Moreover,the finely tuned blend morphology exhibited superior thermal stability,underscoring the significant advantages of the Y-series pendant random copolymerization approach.展开更多
The development of narrow-bandgap polymer donors with complementary absorption and matched energy levels for perylene diimides(PDI)-based nonfullerene acceptors(NFAs)has received little attention.The high-lying highes...The development of narrow-bandgap polymer donors with complementary absorption and matched energy levels for perylene diimides(PDI)-based nonfullerene acceptors(NFAs)has received little attention.The high-lying highest occupied molecular orbital(HOMO)level and low degree of crystallinity of the star donor polymer PCE10 limit its application in PDI-based Organic solar cells(OSCs).In this study,two benzo[1,2-b:4,5-b′]difuran(BDF)-based narrow-bandgap polymer donors,PBDF and PBDFCl,were synthesized to improve the photovoltaic performance of PDI-based OSCs.The smaller BDF moiety with higher electronegativity endows the resulting polymers with stronger aggregation and lower HOMO energy levels.The power conversion efficiency(PCE)value of the PBDF:Ph(PDI)3-based OSCs was 7.24%,which is much higher than that of PCE10-based OSCs(6.09%).Further chlorination of the conjugated side chain elevated the PCE to 8.84%,which is 1.4 times higher than that of PCE10-based OSCs.These results demonstrate the significant contribution of designing novel narrow-bandgap polymer donors to boost the PCE of PDI-based OSCs and highlight the importance of matching the aggregation behaviors of polymeric donor materials with that of NFAs.展开更多
Circularly polarized luminescence(CPL)and two-photon absorption(TPA)materials have garnered considerable attentions due to their minimal energy loss and superior optical penetration[1,2].However,the current challenge ...Circularly polarized luminescence(CPL)and two-photon absorption(TPA)materials have garnered considerable attentions due to their minimal energy loss and superior optical penetration[1,2].However,the current challenge lies in the absence of well-developed strategies for designing materials that combine these two exceptional optical properties.展开更多
Non-fullerene acceptors(NFAs)become an interesting family of organic photovoltaic materials,and have attracted considerable interest for their great potential in manufacturing large-area flexible solar panels by low c...Non-fullerene acceptors(NFAs)become an interesting family of organic photovoltaic materials,and have attracted considerable interest for their great potential in manufacturing large-area flexible solar panels by low cost coating methods[1–5].Recently,our group proposed in the first time an A-DA’D-A molecular strategy and synthesized a new class of non-fullerene acceptor Y6 with a record efficiency above 15%with single junction organic solar cells(OSCs)[6].To further improve the photovoltaic performance of OSCs,many effective strategies have been successfully explored,such as side-chain engineering and extension of fused core and terminal group engineering[7–12].As well-known,PCE of devices is determined by the open circuit voltage(Voc),short-circuit current density(Jsc)and fill factor(FF)[13].Among them,Voc is associated with low-lying highest occupied molecular orbital(HOMO)of donor and lowest unoccupied molecular orbital(LUMO)of acceptor of the active layer[14–16].Side-chain engineering is an effective strategy for manipulating energy levels and improving photovoltaic performance of devices[17–19].For example,introducing the alkyl/alkoxy chains can effectively tune the HOMO/LUMO energy levels[20–22].Tang et al.have reported a novel non-fullerene acceptor ITC6-IC.ITC6-IC has relatively high LUMO level and high Voc than those of ITIC due to the introduction of weak electrondonating hexyl group on thiophene[23].展开更多
Improving the performance and reducing the manufacturing costs are the main directions for the development of organic solar cells in the future.Here,the strategy that uses chemical structure modification to optimize t...Improving the performance and reducing the manufacturing costs are the main directions for the development of organic solar cells in the future.Here,the strategy that uses chemical structure modification to optimize the photoelectric properties is reported.A new narrow bandgap(1.30 eV)chlorinated non-fullerene electron acceptor(Y15),based on benzo[d][1,2,3] triazole with two 3-undecylthieno[2’,3’:4,5] thieno[3,2-b] pyrrole fused-7-heterocyclic ring,with absorption edge extending to the near-infrared(NIR) region,namely A-DA’D-A type structure,is designed and synthesized.Its electrochemical and optoelectronic properties are systematically investigated.Benefitting from its NIR light harvesting,the fabricated photovoltaic devices based on Y15 deliver a high power conversion efficiency(PCE) of 14.13%,when blending with a wide bandgap polymer donor PM6.Our results show that the A-DA’D-A type molecular design and application of near-infrared electron acceptors have the potential to further improve the PCE of polymer solar cells(PSCs).展开更多
Four polymers based on perylenediimide co-polymerized with thiophene, bithiophene, selenophone and thieno[3,2-b]thiophene were investigated as the acceptor materials in all-polymer solar cells. Two different donor pol...Four polymers based on perylenediimide co-polymerized with thiophene, bithiophene, selenophone and thieno[3,2-b]thiophene were investigated as the acceptor materials in all-polymer solar cells. Two different donor polymers, poly[4,8-bis（5-（2-ethylhexyl）thiophen-2-yl）benzo[ 1,2-b;4,5-b＇]dithiophene-2,6-diyl-alt-（4-（2-ethylhexyl）-3-fluorothieno[3,4- b]thiophene）-2-carboxylate-2,6-diyl] （PTB7-Th） and poly[（5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl）-alt-（3,3＇-di（2- dodecyltetradecyl）-2,2＇;5＇,2＂;5＂,2＇-quaterthiophen-5,5＇＂-diyl）] （PffBT4T-2DT）, with suitably complementary absorption spectra and energy levels were applied and examined. Among all different donor-acceptor pairs studied here, the combination of PTB7-Th：poly[NN-bis（1-hexylheptyl）-3,4,9,10-pery,enediimide-1,6/1,7-diyl-alt-2,5-thiophene] （PDI-Th） exhibited the best power conversion efficiency （PCE） of 5.13%, with open-circuit voltage （Vo：） = 0.79 lV, short-circuit current density （Jsc） = 12.35 mA.cm-2 and fill-factor （FF） = 0.52. The polymer of PDI-Th acceptor used here had a regio-irregular backbone, conveniently prepared from a mixture of 1,6- and 1,7-dibromo-PDI. It is also noteworthy that neither additive nor post- treatment is required for obtaining such a cell performance.展开更多
Nonfullerene acceptors(NFAs),which usually possess symmetric skeletons,have drawn great attention in recent years due to their pronounced advantages over the fullerene counterparts.Moreover,breaking the symmetry of NF...Nonfullerene acceptors(NFAs),which usually possess symmetric skeletons,have drawn great attention in recent years due to their pronounced advantages over the fullerene counterparts.Moreover,breaking the symmetry of NFAs could fine tune the molecular dipole,solubility,energy level,intermolecular interaction,molecular packing,crystallinity,etc.,and give rise to improved photovoltaic performance.Currently,there are three main strategies for the design of asymmetric NFAs.This review highlights the recent advances of high-performance asymmetric NFAs and briefly outlooks the materials exploration for the future.展开更多
The active layer of all polymer solar cells(all-PSCs)is composed of a blend of a p-type conjugated polymer(p-CP)as donor and an n-type conjugated polymer(n-CP)as acceptor.All-PSCs possess the advantages of light weigh...The active layer of all polymer solar cells(all-PSCs)is composed of a blend of a p-type conjugated polymer(p-CP)as donor and an n-type conjugated polymer(n-CP)as acceptor.All-PSCs possess the advantages of light weight,thin active layer,mechanical flexibility,low cost solution processing and high stability,but the power conversion efficiency(PCE)of the all-PSCs was limited by the poor photovoltaic performance of the n-CP acceptors before 2016.Since the report of the strategy of polymerized small molecule acceptors(PSMAs)in 2017,the photovoltaic performance of the PSMA-based n-CPs improved rapidly,benefitted from the development of the A-DA’D-A type small molecule acceptors(SMAs).PCE of the all-PSCs based on the PSMA acceptors reached 17%-18%recently.In this review article,we will introduce the development history of the n-CPs,especially the recent research progress of the PSMAs.Particularly,the structure-property relationship of the PSMAs is introduced and discussed.Finally,current challenges and prospects of the n-CP acceptors are analyzed and discussed.展开更多
Non-fullerene organic solar cells have received increasing attentions in these years,and great progresses have been made since 2013.Among them,aromatic di-amide/imide-containing frameworks have shown promising applica...Non-fullerene organic solar cells have received increasing attentions in these years,and great progresses have been made since 2013.Among them,aromatic di-amide/imide-containing frameworks have shown promising applications.The outstanding properties of them are highly associated with their unique electronic and structural features,such as strong electron-withdrawing nature,broad absorption in UVvisible region,tunable HOMO/LUMO energy levels,easy modifications,and excellent chemical,thermal and photochemical stabilities.In this review,we give an overview of recent developments of aromatic diamide/imide-containing small molecules used as electron acceptors for organic solar cells.展开更多
Two acceptor-donor-acceptor(A-D-A)type non-fullerene acceptors(namely WH1 and WH7)containing the oxindole-based bridge are designed and synthesized for polymer solar cells(PSCs)applications.The bridge unit is introduc...Two acceptor-donor-acceptor(A-D-A)type non-fullerene acceptors(namely WH1 and WH7)containing the oxindole-based bridge are designed and synthesized for polymer solar cells(PSCs)applications.The bridge unit is introduced through a precursor(6-bromo-1-octylindoline-2,3-dione)that contains both bromine and carbonyl and provides the feasibility of the Pd-catalyzed cross-coupling reaction and the Knoevenagel condensation,respectively.This facile synthetic approach exhibits the potential to gain high performance non-fullerene acceptors through extendingπ-conjugated backbone with strong light-absorbing building blocks.The synthesis and properties of WH1 and WH7 are demonstrated with different endcap units,then PSCs are fabricated using PBDB-T:WH1 and PBDB-T:WH7 as the active layers,and attain an average power conversion efficiency(PCE)of 2.58%and 6.24%,respectively.Further device physics studies afford the deep insight of structure variation influence on the device performance.This work provides a facile non-fullerene acceptor design strategy and shows how structure variations impact the PSC performance.展开更多
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
Herein,two asymmetric hexacyclic fused small molecule acceptors(SMAs),namely BP4F-HU and BP4F-UU,were synthesized.The elongated outside chains in the BP4F-UU molecule played a crucial role in optimizing the morphology...Herein,two asymmetric hexacyclic fused small molecule acceptors(SMAs),namely BP4F-HU and BP4F-UU,were synthesized.The elongated outside chains in the BP4F-UU molecule played a crucial role in optimizing the morphology of blend film,thereby improving charge mobility and reducing energy loss within the corresponding film.Notably,the PM6:BP4F-UU device exhibited a higher open-circuit voltage(V_(oc))of 0.878 V compared to the PM6:BP4F-HU device with a V_(oc)of 0.863 V.Further,a new wide bandgap SMA named BTP-TA was designed and synthesized as the third component to the PM6:BP4F-UU host binary devices,which showed an ideal complementary absorption spectrum in PM6:BP4F-UU system.In addition,BTP-TA can achieve efficient intermolecular energy transfer to BP4F-UU by fluorescence resonance energy transfer(FRET)pathway,due to the good overlap between the photoluminescence(PL)spectrum of BTP-TA and the absorption region of BP4F-UU.Consequently,ternary devices with 15wt%BTP-TA exhibits broader photon utilization,optimal blend morphology,and reduced charge recombination compared to the corresponding binary devices.Consequently,PM6:BP4F-UU:BTP-TA ternary device achieved an optimal power conversion efficiency(PCE)of 17.83%with simultaneously increased V_(oc)of 0.905 V,short-circuit current density(J_(sc))of 26.14 mA/cm^(2),and fill factor(FF)of 75.38%.展开更多
The results of interaction between CdSe quantum dots and polyaniline were reported. Polyaniline effectively decreases the emission of CdSe quantum dots, and the CdSe luminescence lifetime is decreased by the addition ...The results of interaction between CdSe quantum dots and polyaniline were reported. Polyaniline effectively decreases the emission of CdSe quantum dots, and the CdSe luminescence lifetime is decreased by the addition of polyaniline. The mechanism of the emission observed in CdSe is assumed to result from the energy transfer and from the combination of surface-trapped electrons and holes energy is transferred from CdSe to polyaniline, and polyaniline occupies the hole sites.展开更多
Deep level transient Fourier spectroscopy （DLTFS） measurements are used to characterize the deep impurity levels in n-type 4H-SiC by vanadium ions implantation. Two acceptor levels of vanadium at Ec - 0.81 and Ec - ...Deep level transient Fourier spectroscopy （DLTFS） measurements are used to characterize the deep impurity levels in n-type 4H-SiC by vanadium ions implantation. Two acceptor levels of vanadium at Ec - 0.81 and Ec - 1.02eV with the electron capture cross section of 7.0 × 10^16 and 6.0 × 10^-16 cm^2 are observed, respectively. Low-temperature photoluminescence measurements in the range of 1.4-3.4eV are also performed on the sample, which reveals the formation of two electron traps at 0.80 and 1. 16eV below the conduction band. These traps indicate that vanadium doping leads to the formation of two deep acceptor levels in 4H-SiC,with the location of 0.8±0.01 and 1. 1 ±0.08eV below the conduction band.展开更多
基金supported by the Natural Science Foundation of Zhejiang Province(Nos.LZ23B040001,LY23E030003 and LY24B030005)the National Natural Science Foundation of China(No.22105222)+1 种基金the Interdisciplinary Research Project of Hangzhou Normal University(No.2024JCXK05)the Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application,Soochow University。
文摘The integration of advanced diagnostic and therapeutic capabilities in oncology has given rise to phototheranostics,a field that combines the precision of imaging with the selectivity of light-activated treatments.Due to their pronounced near-infrared(NIR)absorption,tunable molecular structures,and commendable stability,organic photovoltaic non-fullerene acceptors(NFAs)represent a promising frontier in cancer management.Despite the great potential of NFAs in phototheranostics,there is currently a lack of systematic reviews in this field.This review provides a meticulous examination of the current state of NFAs in the field of phototheranostics,highlighting the strategic approaches to spectral red-shifting that enhance tissue penetration and therapeutic efficacy.It dissects the link between molecular architecture and performance across key therapeutic and diagnostic modalities,including photothermal therapy(PTT),photodynamic therapy(PDT),and fluorescence imaging(FLI).In addition,the review presents a concise analysis of the challenges and milestones in the clinical translation of NFAs,offering insights into the innovations required to overcome existing barriers.
基金support from the National Natural Science Foundation of China(Nos.52373176,52073067)。
文摘Benzotriazole(BTA)-based A_(2)-A_1-D-A_1-A_(2)type wide-bandgap(WBG)non-fullerene acceptors(NFAs)have shown promising potential in indoor photovoltaic,and in-depth investigation of their structure-property relationship is of great significance.Herein,we explored the chlorination effect of the side chain on the terminals.We introduced Cl atoms into the benzyl side chains in parent BTA5 to synthesize two NFAs,BTA5-Cl with mono-chlorinated benzyl groups and BTA5-2Cl containing bi-chlorinated benzyl groups.We chose D18-Cl with deep-energy levels and strong crystallinity to pair with these three acceptors,affording high photovoltage and photocurrent.With the stepwise chlorination,the open-circuit voltage(V_(OC))values decrease from 1.28,1.22,to 1.20 V,while the corresponding power conversion efficiencies(PCEs)improve from 5.07%,9.15%,to 10.96%.Compared with BTA5-based OSCs,introducing Cl atoms downshifts the energy levels and slightly increases the non-radiative energy loss(0.14<0.17<0.19 e V),resulting in a sequential decrease in VO C.However,more chlorine atom replacements produce more effective exciton dissociation,higher charge transfer,and balanced carrier mobility in the blend films,ultimately achieving better PCEs.This work indicates that chlorination of the benzyl group on the terminals can improve the device's performance,implying good application potential in indoor photovoltaics.
基金financially supported by the Guangdong Major Project of Basic and Applied Basic Research(No.2023B0303000002)the Shenzhen Key Laboratory of Advanced Energy Storage(ZDSYS20220401141000001)the High level of special funds(G03034K001)。
文摘High-voltage lithium(Li)metal batteries(LMBs)face substantial challenges,including Li dendrite growth and instability in high-voltage cathodes such as LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM811),which impede their practical applications and long-term stability.To address these challenges,tris(pentafluorophenyl)borane additive as an electron acceptor is introduced into an ethyl methyl carbonate/fluoroethylene carbonate-based electrolyte.This approach effectively engineers robust dual interfaces on the Li metal anode and the NCM811 cathode,thereby mitigating dendritic growth of Li and enhancing the stability of the cathode.This additive-driven strategy enables LMBs to operate at ultra-high voltages up to 4.7 V.Consequently,Li||Cu cells achieve a coulombic efficiency of 98.96%,and Li||Li symmetric cells extend their cycle life to an impressive 4000 h.Li||NCM811 full cells maintain a high capacity retention of 87.8%after 100 cycles at 4.7 V.Additionally,Li||LNMO full cells exhibit exceptional rate capability,delivering 132.2 mAh g^(-1)at 10 C and retaining 95.0%capacity after 250 cycles at 1 C and 5 V.As a result,NCM811||graphite pouch cells maintain a 93.4%capacity retention after 1100 cycles at 1 C.These findings underscore the efficacy of additive engineering in addressing Li dendrite formation and instability of cathode under high voltage,thereby paving the road for durable,high-performance LMBs.
基金financially supported by the National Natural Science Foundation of China(Nos.22465018,52163018 and 22405107)of ChinaJiangxi Provincial Department of Science and Technology(Nos.20232BBE50026,jxsq2023102153,20232BAB21302 and 2024SSY05132)Jiangxi Academy of Sciences(Nos.2023YYB07,2022YSBG22031,2022YJC2019,2022YJC2017,2023YSBG21017,2022YYB10,2022YRCS002,2023YJC1001,and 2023YSBG22025)。
文摘The asymmetric molecular design strategy,with advantages in modulating the molecular dipole moment and intermolecular interactions and achieving more favorable molecular packing and orientation,has been an effective approach for designing high-performance nonfullerene acceptors(NFAs).Herein,two asymmetric NFAs,Y-CN-2F and Y-CN-2Cl,were designed and synthesized by introducing a linear alkyl chain terminated with the 4-cyanobiphenyl group,a well-known mesogenic unit,at one of the inner pyrrole positions instead of the normal 2-butyloctyl branched alkyl chain.The difference between Y-CN-2F and Y-CN-2Cl is the terminated IC-groups,which was modified with F and Cl halogens,respectively.Both NFAs displayed strong absorption in the near-infrared to visible-light range,which is complementary to that of typical medium-bandgap donor polymers.After optimization with D18 donor in organic solar cells(OSCs),Y-CN-2F and Y-CN-2Cl provided comparable power conversion efficiencies(PCEs)of 15.33%and 15.88%.While the D18:Y-CN-2F based devices displayed higher fill factors(FFs),those based on D18:Y-CN-2Cl exhibited higher current densities and open-circuit voltages.The Y-CN-2Cl film showed longer light absorption than YCN-2F,which is beneficial for more light harvesting.Moreover,D18:Y-CN-2Cl displayed a lower fluorescence lifetime and faster carrier transfer processes,which could be attributed to its higher mobility.For the D18:Y-CN-2F blended film,a more pronounced fiber network structure and balanced carrier mobility were observed,which contributed to the higher FFs values.This work presents new efforts to develop more asymmetric NFAs with specific functional segments for efficient organic electronics.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.22279094 and 22409149)Hubei Provincial Natural Science Foundation(No.2024 AFB068)Fundamental Research Funds for the Central Universities。
文摘Polymer acceptor configuration and aggregation behavior are critical in determining the photovoltaic performance of all-polymer solar cells(all-PSCs).Effectively manipulating polymer self-aggregation through structural design to optimize the blend morphology remains challenging.Herein,we present a simple yet effective design strategy to modulate the aggregation behavior of the Y-series-based polymer acceptor PY-V-γby introducing a pendant-fluorinated Y-series acceptor(Y2F-ET)into the main-conjugated backbone.Two random copolymer acceptors(PY-EY-5 and PY-EY-20)were synthesized with varying molar fractions of Y2F-ET pendant monomers.Our findings revealed that both the solution-phase and solid-state aggregation behaviors were progressively suppressed as the Y2F-ET content increased.Compared to the highly self-aggregating PY-V-γ-based all-PSCs,the more amorphous PY-EY-5 enabled devices to achieve an increased device efficiency from 17.31%to 18.45%,which is attributed to the slightly smaller polymer phase-separation domain sizes and reduced molecular aggregation in the PM6:PY-EY-5 blend.Moreover,the finely tuned blend morphology exhibited superior thermal stability,underscoring the significant advantages of the Y-series pendant random copolymerization approach.
基金supported by the National Natural Science Foundation of China(Nos.52273195 and 51973169)Young Top-notch Talent Cultivation Program of Hubei Province,Natural Science Foundation of Hubei Province(No.2022CFB097)。
文摘The development of narrow-bandgap polymer donors with complementary absorption and matched energy levels for perylene diimides(PDI)-based nonfullerene acceptors(NFAs)has received little attention.The high-lying highest occupied molecular orbital(HOMO)level and low degree of crystallinity of the star donor polymer PCE10 limit its application in PDI-based Organic solar cells(OSCs).In this study,two benzo[1,2-b:4,5-b′]difuran(BDF)-based narrow-bandgap polymer donors,PBDF and PBDFCl,were synthesized to improve the photovoltaic performance of PDI-based OSCs.The smaller BDF moiety with higher electronegativity endows the resulting polymers with stronger aggregation and lower HOMO energy levels.The power conversion efficiency(PCE)value of the PBDF:Ph(PDI)3-based OSCs was 7.24%,which is much higher than that of PCE10-based OSCs(6.09%).Further chlorination of the conjugated side chain elevated the PCE to 8.84%,which is 1.4 times higher than that of PCE10-based OSCs.These results demonstrate the significant contribution of designing novel narrow-bandgap polymer donors to boost the PCE of PDI-based OSCs and highlight the importance of matching the aggregation behaviors of polymeric donor materials with that of NFAs.
基金supported by NSFC(22271282)the Self-deployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences with the grant number of CXZX-2022-JQ04.
文摘Circularly polarized luminescence(CPL)and two-photon absorption(TPA)materials have garnered considerable attentions due to their minimal energy loss and superior optical penetration[1,2].However,the current challenge lies in the absence of well-developed strategies for designing materials that combine these two exceptional optical properties.
文摘Non-fullerene acceptors(NFAs)become an interesting family of organic photovoltaic materials,and have attracted considerable interest for their great potential in manufacturing large-area flexible solar panels by low cost coating methods[1–5].Recently,our group proposed in the first time an A-DA’D-A molecular strategy and synthesized a new class of non-fullerene acceptor Y6 with a record efficiency above 15%with single junction organic solar cells(OSCs)[6].To further improve the photovoltaic performance of OSCs,many effective strategies have been successfully explored,such as side-chain engineering and extension of fused core and terminal group engineering[7–12].As well-known,PCE of devices is determined by the open circuit voltage(Voc),short-circuit current density(Jsc)and fill factor(FF)[13].Among them,Voc is associated with low-lying highest occupied molecular orbital(HOMO)of donor and lowest unoccupied molecular orbital(LUMO)of acceptor of the active layer[14–16].Side-chain engineering is an effective strategy for manipulating energy levels and improving photovoltaic performance of devices[17–19].For example,introducing the alkyl/alkoxy chains can effectively tune the HOMO/LUMO energy levels[20–22].Tang et al.have reported a novel non-fullerene acceptor ITC6-IC.ITC6-IC has relatively high LUMO level and high Voc than those of ITIC due to the introduction of weak electrondonating hexyl group on thiophene[23].
基金financially supported by the National Natural Science Foundation of China (Nos.51811530096, 21875286)the National Key Research & Development Projects of China (No.2017YFA0206600)Science Fund for Distinguished Young Scholars of Hunan Province (No.2017JJ1029)
文摘Improving the performance and reducing the manufacturing costs are the main directions for the development of organic solar cells in the future.Here,the strategy that uses chemical structure modification to optimize the photoelectric properties is reported.A new narrow bandgap(1.30 eV)chlorinated non-fullerene electron acceptor(Y15),based on benzo[d][1,2,3] triazole with two 3-undecylthieno[2’,3’:4,5] thieno[3,2-b] pyrrole fused-7-heterocyclic ring,with absorption edge extending to the near-infrared(NIR) region,namely A-DA’D-A type structure,is designed and synthesized.Its electrochemical and optoelectronic properties are systematically investigated.Benefitting from its NIR light harvesting,the fabricated photovoltaic devices based on Y15 deliver a high power conversion efficiency(PCE) of 14.13%,when blending with a wide bandgap polymer donor PM6.Our results show that the A-DA’D-A type molecular design and application of near-infrared electron acceptors have the potential to further improve the PCE of polymer solar cells(PSCs).
基金financially supported by the National Natural Science Foundation of China(Nos.21674001 and 51473003)
文摘Four polymers based on perylenediimide co-polymerized with thiophene, bithiophene, selenophone and thieno[3,2-b]thiophene were investigated as the acceptor materials in all-polymer solar cells. Two different donor polymers, poly[4,8-bis（5-（2-ethylhexyl）thiophen-2-yl）benzo[ 1,2-b;4,5-b＇]dithiophene-2,6-diyl-alt-（4-（2-ethylhexyl）-3-fluorothieno[3,4- b]thiophene）-2-carboxylate-2,6-diyl] （PTB7-Th） and poly[（5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl）-alt-（3,3＇-di（2- dodecyltetradecyl）-2,2＇;5＇,2＂;5＂,2＇-quaterthiophen-5,5＇＂-diyl）] （PffBT4T-2DT）, with suitably complementary absorption spectra and energy levels were applied and examined. Among all different donor-acceptor pairs studied here, the combination of PTB7-Th：poly[NN-bis（1-hexylheptyl）-3,4,9,10-pery,enediimide-1,6/1,7-diyl-alt-2,5-thiophene] （PDI-Th） exhibited the best power conversion efficiency （PCE） of 5.13%, with open-circuit voltage （Vo：） = 0.79 lV, short-circuit current density （Jsc） = 12.35 mA.cm-2 and fill-factor （FF） = 0.52. The polymer of PDI-Th acceptor used here had a regio-irregular backbone, conveniently prepared from a mixture of 1,6- and 1,7-dibromo-PDI. It is also noteworthy that neither additive nor post- treatment is required for obtaining such a cell performance.
基金supported by the National Natural Science Foundation of China(Nos.22075069,51933001)Natural Science Foundation of Henan Province(No.212300410002)Program sponsored by Henan Province(Nos.23ZX002,ZYQR201912163).
文摘Nonfullerene acceptors(NFAs),which usually possess symmetric skeletons,have drawn great attention in recent years due to their pronounced advantages over the fullerene counterparts.Moreover,breaking the symmetry of NFAs could fine tune the molecular dipole,solubility,energy level,intermolecular interaction,molecular packing,crystallinity,etc.,and give rise to improved photovoltaic performance.Currently,there are three main strategies for the design of asymmetric NFAs.This review highlights the recent advances of high-performance asymmetric NFAs and briefly outlooks the materials exploration for the future.
基金financially supported by the National Natural Science Foundation of China(Nos.61904181,51820105003,52173188 and 21734008)the Basic and Applied Basic Research Major Program of Guangdong Province(No.2019B030302007)。
文摘The active layer of all polymer solar cells(all-PSCs)is composed of a blend of a p-type conjugated polymer(p-CP)as donor and an n-type conjugated polymer(n-CP)as acceptor.All-PSCs possess the advantages of light weight,thin active layer,mechanical flexibility,low cost solution processing and high stability,but the power conversion efficiency(PCE)of the all-PSCs was limited by the poor photovoltaic performance of the n-CP acceptors before 2016.Since the report of the strategy of polymerized small molecule acceptors(PSMAs)in 2017,the photovoltaic performance of the PSMA-based n-CPs improved rapidly,benefitted from the development of the A-DA’D-A type small molecule acceptors(SMAs).PCE of the all-PSCs based on the PSMA acceptors reached 17%-18%recently.In this review article,we will introduce the development history of the n-CPs,especially the recent research progress of the PSMAs.Particularly,the structure-property relationship of the PSMAs is introduced and discussed.Finally,current challenges and prospects of the n-CP acceptors are analyzed and discussed.
基金financially supported by NSFC(Nos.21190032,21372226)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA09020000)
文摘Non-fullerene organic solar cells have received increasing attentions in these years,and great progresses have been made since 2013.Among them,aromatic di-amide/imide-containing frameworks have shown promising applications.The outstanding properties of them are highly associated with their unique electronic and structural features,such as strong electron-withdrawing nature,broad absorption in UVvisible region,tunable HOMO/LUMO energy levels,easy modifications,and excellent chemical,thermal and photochemical stabilities.In this review,we give an overview of recent developments of aromatic diamide/imide-containing small molecules used as electron acceptors for organic solar cells.
基金National Natural Science Foundation of China(No.21805032)Natural Science Foundation of Shanghai,China(No.19ZR1401400)Fundamental Research Funds for the Central Universities,China(No.20D128502).
文摘Two acceptor-donor-acceptor(A-D-A)type non-fullerene acceptors(namely WH1 and WH7)containing the oxindole-based bridge are designed and synthesized for polymer solar cells(PSCs)applications.The bridge unit is introduced through a precursor(6-bromo-1-octylindoline-2,3-dione)that contains both bromine and carbonyl and provides the feasibility of the Pd-catalyzed cross-coupling reaction and the Knoevenagel condensation,respectively.This facile synthetic approach exhibits the potential to gain high performance non-fullerene acceptors through extendingπ-conjugated backbone with strong light-absorbing building blocks.The synthesis and properties of WH1 and WH7 are demonstrated with different endcap units,then PSCs are fabricated using PBDB-T:WH1 and PBDB-T:WH7 as the active layers,and attain an average power conversion efficiency(PCE)of 2.58%and 6.24%,respectively.Further device physics studies afford the deep insight of structure variation influence on the device performance.This work provides a facile non-fullerene acceptor design strategy and shows how structure variations impact the PSC performance.
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the National Natural Science Foundation of China(Nos.52125306 and 21875286)。
文摘Herein,two asymmetric hexacyclic fused small molecule acceptors(SMAs),namely BP4F-HU and BP4F-UU,were synthesized.The elongated outside chains in the BP4F-UU molecule played a crucial role in optimizing the morphology of blend film,thereby improving charge mobility and reducing energy loss within the corresponding film.Notably,the PM6:BP4F-UU device exhibited a higher open-circuit voltage(V_(oc))of 0.878 V compared to the PM6:BP4F-HU device with a V_(oc)of 0.863 V.Further,a new wide bandgap SMA named BTP-TA was designed and synthesized as the third component to the PM6:BP4F-UU host binary devices,which showed an ideal complementary absorption spectrum in PM6:BP4F-UU system.In addition,BTP-TA can achieve efficient intermolecular energy transfer to BP4F-UU by fluorescence resonance energy transfer(FRET)pathway,due to the good overlap between the photoluminescence(PL)spectrum of BTP-TA and the absorption region of BP4F-UU.Consequently,ternary devices with 15wt%BTP-TA exhibits broader photon utilization,optimal blend morphology,and reduced charge recombination compared to the corresponding binary devices.Consequently,PM6:BP4F-UU:BTP-TA ternary device achieved an optimal power conversion efficiency(PCE)of 17.83%with simultaneously increased V_(oc)of 0.905 V,short-circuit current density(J_(sc))of 26.14 mA/cm^(2),and fill factor(FF)of 75.38%.
基金Major Foundation of Chinese Academy of Sciences(No 2002CD713802)National High Technology Develop-ment Program(No 2002AA302203)
文摘The results of interaction between CdSe quantum dots and polyaniline were reported. Polyaniline effectively decreases the emission of CdSe quantum dots, and the CdSe luminescence lifetime is decreased by the addition of polyaniline. The mechanism of the emission observed in CdSe is assumed to result from the energy transfer and from the combination of surface-trapped electrons and holes energy is transferred from CdSe to polyaniline, and polyaniline occupies the hole sites.
文摘Deep level transient Fourier spectroscopy （DLTFS） measurements are used to characterize the deep impurity levels in n-type 4H-SiC by vanadium ions implantation. Two acceptor levels of vanadium at Ec - 0.81 and Ec - 1.02eV with the electron capture cross section of 7.0 × 10^16 and 6.0 × 10^-16 cm^2 are observed, respectively. Low-temperature photoluminescence measurements in the range of 1.4-3.4eV are also performed on the sample, which reveals the formation of two electron traps at 0.80 and 1. 16eV below the conduction band. These traps indicate that vanadium doping leads to the formation of two deep acceptor levels in 4H-SiC,with the location of 0.8±0.01 and 1. 1 ±0.08eV below the conduction band.
