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
Despite the significant progress made recently in all-polymer solar cells(all-PSCs),it is still quite challenging to achieve high open-circuit voltage(V_(oc))and short-circuit current density(J_(sc))simultaneously in ...Despite the significant progress made recently in all-polymer solar cells(all-PSCs),it is still quite challenging to achieve high open-circuit voltage(V_(oc))and short-circuit current density(J_(sc))simultaneously in order to further improve their performance.The recent strategy of using selenophene to replace thiophene on the Y6 based polymer acceptors has resulted in significantly improved J_(sc)s of the resulting all-PSCs.However,such modifications have also depressed V_(oc),which compromises the overall performance of the devices.Herein,we present the design and synthesis of a novel polymer acceptor,PYT-1S1Se,created by inserting an asymmetrical selenophene-fused framework to precisely manipulate optical absorption and electronic properties.Compared with the selenium-free analog,PYT-2S,and symmetrical selenium-fused analog,PYT-2Se,the PYT-1S1Se derived all-PSCs not only deliver optimized J_(sc)(24.1 mA cm^(−2))and V_(oc)(0.926 V)metrics,but also exhibit a relatively low energy loss of 0.502 eV.Consequently,these devices obtain a record-high power conversion efficiency(PCE)of 16.3%in binary all-PSCs.This work demonstrates an effective molecular design strategy for balancing the trade-off between V_(oc) and J_(sc) to achieve highefficiency all-PSCs.展开更多
Despite the rapidly increased power conversion efficiency(PCE)of perovskite solar cells(PVSCs),it is still quite challenging to bring such promising photovoltaic technology to commercialization.One of the challenges i...Despite the rapidly increased power conversion efficiency(PCE)of perovskite solar cells(PVSCs),it is still quite challenging to bring such promising photovoltaic technology to commercialization.One of the challenges is the upscaling from small-sized lab devices to large-scale modules or panels for production.Currently,most of the efficient inverted PVSCs are fabricated on top of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine](PTAA),which is a commonly used hole-transporting material,using spin-coating method to be incompatible with large-scale film deposition.Therefore,it is important to develop proper coating methods such as blade-coating or slot-die coating that can be compatible for producing large-area,high-quality perovskite thin films.It is found that due to the poor wettability of PTAA,the blade-coated perovskite films on PTAA surface are often inhomogeneous with large number of voids at the buried interface of the perovskite layer.To solve this problem,self-assembled monolayer(SAM)-based hole-extraction layer(HEL)with tunable headgroups on top of the SAM can be modified to provide better wettability and facilitate better interactions with the perovskite coated on top to passivate the interfacial defects.The more hydrophilic SAM surface can also facilitate the nucleation and growth of perovskite films fabricated by blade-coating methods,forming a compact and uniform buried interface.In addition,the SAM molecules can also be modified so their highest occupied molecular orbital(HOMO)levels can have a better energy alignment with the valence band maxima(VBM)of perovskite.Benefitted by the high-quality buried interface of perovskite on SAM-based substrate,the champion device shows a PCE of 18.47%and 14.64%for the devices with active areas of 0.105 cm^(2) and 1.008 cm^(2),respectively.In addition,the SAM-based device exhibits decent stability,which can maintain 90%of its initial efficiency after continuous operation for over 500 h at 40℃ in inert atmosphere.Moreover,the SAM-based perovskite mini-module exhibits a PCE of 14.13%with an aperture area of 18.0 cm^(2).This work demonstrates the great potential of using SAMs as efficient HELs for upscaling PVSCs and producing high-quality buried interface for large-area perovskite films.展开更多
The persistency of passivation and scalable uniformity are vital issues that limit the improvement of performance and stability of large-area perovskite solar modules(PSMs).Here,we design a bilayer interface engineeri...The persistency of passivation and scalable uniformity are vital issues that limit the improvement of performance and stability of large-area perovskite solar modules(PSMs).Here,we design a bilayer interface engineering strategy that takes advantage of the stability and passivation ability of low-dimensional perovskite and the dipole layer.Introducing phenethylammonium iodide(PEAI)can form 2D/3D heterojunctions on the perovskite surface and effectively passivate defects of perovskite film.Interestingly,the upper piperazinium iodide(PI)layer can still form surface dipoles on the 2D/3D perovskite surface to optimize energy-level alignment.Moreover,the bilayer interface engineering enables large-area perovskite films with uniform surface morphology,lower trap-state density and stability against environmental stress factors.The final devices achieved a small-area PCE of 25.20% and a large-area(1 cm^(2))PCE of 23.96%.A perovskite mini-module(5×5 cm^(2) with an active area of 14.28 cm^(2))could also be fabricated to achieve a PCE of 23.19%,ranking it among the highest for inverted PSMs.Additionally,the device could retain over 93% of its initial efficiency after MPP tracking at 45℃ for 1280 h.This study successfully demonstrates a bilayer interface engineering with respective functions,offering valuable insights for producing efficient and stable large-area PSCs.展开更多
Photovoltaics,as a green technology for converting solar energy into electricity,have shown great promise to address the energy and environmental challenges for the sustainability of human society.In recent years,two ...Photovoltaics,as a green technology for converting solar energy into electricity,have shown great promise to address the energy and environmental challenges for the sustainability of human society.In recent years,two types of photovoltaics,consisting of organic semiconductors or perovskites as light absorbers,have experienced a rapid development.The development of organic solar cells(OSC)can be dated back to 1986,since the discovery of a bi layer OSC by Di.C.W.Tang.Nowadays,OSCs made with polymer donors and small molecule acceptors have surpassed power conversion efficiencies(PCEs)of 16%for single-junction and 17%for tandem devices,through integrated innovative efforts on materials,interfaces,and device architectures.展开更多
CONSPECTUS:Along with the rapid industrialization of human society over the past century,incessant energy consumption and endless damage to the environment have aroused growing attention for seeking clean and renewabl...CONSPECTUS:Along with the rapid industrialization of human society over the past century,incessant energy consumption and endless damage to the environment have aroused growing attention for seeking clean and renewable energy sources.Photovoltaics(PV)that can directly harvest and transform sunlight into electricity have shown great potential in achieving this goal.Especially for solution-processed thin-film solar cells,their extremely cost-effective and facile processing methods compatible with different substrates at large scales exhibit unique advantages over conventional PVs based on crystalline silicon.Various types of solutionprocessed thin-film PVs have been achieving or already exceeded 15%power conversion efficiency(PCE)through the numerous efforts of researchers.Organic solar cells(OSCs)and organic−inorganic hybrid perovskite solar cells(PVSCs)are the most well-known emerging solution-processed thin-film solar cells that have attracted great interest recently(the PCE of PVSCs soared form 3.8%to over 25%in the past decade).Usually,photogenerated excitons will form as a response to illumination in the active layer,then dissociate into charge carriers,travel in between layers,and finally get collected by electrodes of the device.Besides the broad exploration of active layer materials,suitably matched charge-transporting layers and electrodes also play a vital role in achieving high PCE and stability in PV devices.Furthermore,interfaces between different functional layers created during solution processing need to be carefully addressed to ensure efficient charge transport and prevent degradation.The utilization of proper interfacial materials to modify the chemical and electrical properties at interfaces has become an effective strategy to enhance the performance of PV.Therefore,it is important to develop a comprehensive understanding into the correlation between interfacial properties and charge carrier dynamics and establish molecular design principles for interfacial materials to realize commercialization of emerging PVs.展开更多
Additives play a crucial role in enhancing the photovoltaic performance of polymer solar cells(PSCs).However,the typical additives used to optimize blend morphology of PSCs are still high boiling-point solvents,while ...Additives play a crucial role in enhancing the photovoltaic performance of polymer solar cells(PSCs).However,the typical additives used to optimize blend morphology of PSCs are still high boiling-point solvents,while their trace residues may reduce device stability.Herein,an effective strategy of“solidification of solvent additive(SSA)”has been developed to convert additive from liquid to solid,by introducing a covalent bond into low-cost solvent diphenyl sulfide(DPS)to synthesize solid dibenzothiophene(DBT)in one-step,which achieves optimized morphology thus promoting efficiency and device stability.Owing to the fine planarity and volatilization of DBT,the DBT-processed films achieve ordered molecular crystallinity and suitable phase separation compared to the additive-free or DPS-treated ones.Importantly,the DBT-processed device also possesses improved light absorption,enhanced charge transport,and thus a champion efficiency of 17.9%is achieved in the PM6:Y6-based PSCs with an excellent additive component tolerance,reproducibility,and stability.Additionally,the DBT-processed PM6:L8-BO-based PSCs are further fabricated to study the universality of SSA strategy,offering an impressive efficiency approaching19%as one of the highest values in binary PSCs.In conclusion,this article developed a promising strategy named SSA to boost efficiency and improve stability of PSCs.展开更多
Photomultiplication-type polymer photodetectors(PM-PPDs)were achieved with polymer P3HT as donor and PY3Se-1V as acceptor based on structure of ITO/PEDOT:PSS/active layer/Al.The optimal weight ratio of P3HT to PY3Se-1...Photomultiplication-type polymer photodetectors(PM-PPDs)were achieved with polymer P3HT as donor and PY3Se-1V as acceptor based on structure of ITO/PEDOT:PSS/active layer/Al.The optimal weight ratio of P3HT to PY3Se-1V is about 100:3.Amounts of isolated electron traps are formed with PY3Se-1V surrounded by P3HT due to rather less content of PY3Se-1V in active layers and about 0.94 e V energy offset between the lowest unoccupied molecular orbitals(LUMO)of P3HT and PY3Se-1V.The optimal PM-PPDs exhibit broad spectral response from 350 to 950 nm and external quantum efficiency(EQE)values of68,200%at 360 nm,26,400%at 630 nm and 19,500%at 850 nm under-15 V bias.The working mechanism of PM-PPDs is attributed to the interfacial trap-assisted hole tunneling injection from external circuit.The performance of PM-PPDs can be further improved by incorporating appropriate PMBBDT with high hole mobility as the third component.The EQE values of optimal ternary PM-PPDs are increased to 105,000%at 360 nm,40,000%at 630 nm and 31,800%at 850 nm under-15 V bias,benefiting from the enhanced hole transport in ternary active layers.The optimal ternary PM-PPDs were successfully applied in a light-controlled circuit to turn on or turn off light emitting diode(LED).展开更多
Before 2015,only few organic solar cells(OSCs)obtained power conversion efficiencies(PCEs)over 10%because the commonly used fullerene derivatives as acceptors have narrow absorption,low extinction coefficient,and are ...Before 2015,only few organic solar cells(OSCs)obtained power conversion efficiencies(PCEs)over 10%because the commonly used fullerene derivatives as acceptors have narrow absorption,low extinction coefficient,and are difficult to adjust energy levels.To overcome these shortcomings,in 2015,Zhan et al.[1]developed acceptor(A)-donor(D)-A-type fused-ring small-molecule acceptors(SMAs)with good planarity and strong intramolecular charge transfer(ICT)effect to fulfill both broad absorption and high extinction coefficient,offering the revolutionary PCEs of 13%–15%.In 2019,another milestone SMA(Y6)with A-DA′D-A structure was developed by Zou et al.展开更多
Since human society has been rapidly industrializing over the past century,excessive energy consumption and environmental damage have raised awareness of the need for clean,renewable energy sources.Especially after th...Since human society has been rapidly industrializing over the past century,excessive energy consumption and environmental damage have raised awareness of the need for clean,renewable energy sources.Especially after the outbreak of the Russian-Ukrainian war,the development of alternative energy issue has been elevated to an unprecedented strategic level.Solar energy,as one of the clean and renewable energies,is experiencing a historical stage of changing its role from supplementary energy to alternative energy.The exploration of photovoltaic(PV)cells with newmaterials and structures is urgent tomeet the demand of achieving carbon-peak and carbon-neutralization goals.展开更多
Organic photovoltaics(OPVs)represent one of the most promising photovoltaic technologies owing to their high capacity to convert solar energy to electricity.With the continuous structure upgradation of photovoltaic ma...Organic photovoltaics(OPVs)represent one of the most promising photovoltaic technologies owing to their high capacity to convert solar energy to electricity.With the continuous structure upgradation of photovoltaic materials,especially that of non-fullerene acceptors(NFAs),the OPV field has witnessed rapid progress with power conversion efficiency(PCE)exceeding 19%.However,it remains challenging to overcome the intrinsic trade-off between the photocurrent and photovoltage,restricting the further promotion of the OPV efficiency.In this regard,it is urgent to further tailor the structure of NFAs to broaden their absorption spectra while mitigating the energy loss of relevant devices concomitantly.Heteroatom substitution on the fused-ringπ-core of NFAs is an efficient way to achieve this goal.In addition to improve the nearinfrared light harvest by strengthening the intramolecular charge transfer,it can also enhance the molecular stacking via forming multiple noncovalent interactions,which is favorable for reducing the energetic disorder.Therefore,in this review we focus on the design rules of NFAs,including the polymerized NFAs,of which the core moiety is substituted by various kinds of heteroatoms.We also afford a comprehensive understanding on the structure–propertyperformance relationships of these NFAs.Finally,we anticipate the challenges restricting the efficiency promotion and industrial utilization of OPV,and provide potential solutions based on the further heteroatom optimization on NFA core-moiety.展开更多
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supported by the APRC Grant of the City University of Hong Kong(9380086)Innovation and Technology Fund(ITS/497/18FP,GHP/021/18SZ)+7 种基金the Office of Naval Research(N00014-201-2191)the GRF grant(11307621)from the Research Grants Council of Hong Kongthe National Natural Science Foundation of China(21905103)the Natural Science Foundation of Guangdong Province(2019A1515010761,2019A1515011131)Guangdong Major Project of Basic and Applied Basic Research(2019B030302007)Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials(2019B121205002)the Fundamental Research(Discipline Arrangement)Project funding from the Shenzhen Science and Technology Innovation Committee(JCYJ20180507181718203)US Office of Naval Research Contract N0001420-1-2116 for support。
文摘Despite the significant progress made recently in all-polymer solar cells(all-PSCs),it is still quite challenging to achieve high open-circuit voltage(V_(oc))and short-circuit current density(J_(sc))simultaneously in order to further improve their performance.The recent strategy of using selenophene to replace thiophene on the Y6 based polymer acceptors has resulted in significantly improved J_(sc)s of the resulting all-PSCs.However,such modifications have also depressed V_(oc),which compromises the overall performance of the devices.Herein,we present the design and synthesis of a novel polymer acceptor,PYT-1S1Se,created by inserting an asymmetrical selenophene-fused framework to precisely manipulate optical absorption and electronic properties.Compared with the selenium-free analog,PYT-2S,and symmetrical selenium-fused analog,PYT-2Se,the PYT-1S1Se derived all-PSCs not only deliver optimized J_(sc)(24.1 mA cm^(−2))and V_(oc)(0.926 V)metrics,but also exhibit a relatively low energy loss of 0.502 eV.Consequently,these devices obtain a record-high power conversion efficiency(PCE)of 16.3%in binary all-PSCs.This work demonstrates an effective molecular design strategy for balancing the trade-off between V_(oc) and J_(sc) to achieve highefficiency all-PSCs.
基金A.K.Y.J.thanks the sponsorship of the Lee Shau-Kee Chair Professor(Materials Science),and the support from the APRC Grant of the City University of Hong Kong(No.9380086)the GRF grant(No.11307621)from the Research Grants Council of Hong Kong,Guangdong Major Project of Basic and Applied Basic Research(No.2019B030302007)Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials(No.2019B121205002).
文摘Despite the rapidly increased power conversion efficiency(PCE)of perovskite solar cells(PVSCs),it is still quite challenging to bring such promising photovoltaic technology to commercialization.One of the challenges is the upscaling from small-sized lab devices to large-scale modules or panels for production.Currently,most of the efficient inverted PVSCs are fabricated on top of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine](PTAA),which is a commonly used hole-transporting material,using spin-coating method to be incompatible with large-scale film deposition.Therefore,it is important to develop proper coating methods such as blade-coating or slot-die coating that can be compatible for producing large-area,high-quality perovskite thin films.It is found that due to the poor wettability of PTAA,the blade-coated perovskite films on PTAA surface are often inhomogeneous with large number of voids at the buried interface of the perovskite layer.To solve this problem,self-assembled monolayer(SAM)-based hole-extraction layer(HEL)with tunable headgroups on top of the SAM can be modified to provide better wettability and facilitate better interactions with the perovskite coated on top to passivate the interfacial defects.The more hydrophilic SAM surface can also facilitate the nucleation and growth of perovskite films fabricated by blade-coating methods,forming a compact and uniform buried interface.In addition,the SAM molecules can also be modified so their highest occupied molecular orbital(HOMO)levels can have a better energy alignment with the valence band maxima(VBM)of perovskite.Benefitted by the high-quality buried interface of perovskite on SAM-based substrate,the champion device shows a PCE of 18.47%and 14.64%for the devices with active areas of 0.105 cm^(2) and 1.008 cm^(2),respectively.In addition,the SAM-based device exhibits decent stability,which can maintain 90%of its initial efficiency after continuous operation for over 500 h at 40℃ in inert atmosphere.Moreover,the SAM-based perovskite mini-module exhibits a PCE of 14.13%with an aperture area of 18.0 cm^(2).This work demonstrates the great potential of using SAMs as efficient HELs for upscaling PVSCs and producing high-quality buried interface for large-area perovskite films.
基金the APRC Grant of the City University of Hong Kong(9380086)the TCFS Grant(GHP/018/20SZ)and MRP Grant(MRP/040/21X)from the Innovation and Technology Commission of Hong Kong+3 种基金the Green Tech Fund(202020164)from the Environment and Ecology Bureau of Hong Kongthe GRF grants(11307621,11316422)from the Research Grants Council of Hong KongGuangdong Major Project of Basic and Applied Basic Research(2019B030302007)Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials(2019B121205002).
文摘The persistency of passivation and scalable uniformity are vital issues that limit the improvement of performance and stability of large-area perovskite solar modules(PSMs).Here,we design a bilayer interface engineering strategy that takes advantage of the stability and passivation ability of low-dimensional perovskite and the dipole layer.Introducing phenethylammonium iodide(PEAI)can form 2D/3D heterojunctions on the perovskite surface and effectively passivate defects of perovskite film.Interestingly,the upper piperazinium iodide(PI)layer can still form surface dipoles on the 2D/3D perovskite surface to optimize energy-level alignment.Moreover,the bilayer interface engineering enables large-area perovskite films with uniform surface morphology,lower trap-state density and stability against environmental stress factors.The final devices achieved a small-area PCE of 25.20% and a large-area(1 cm^(2))PCE of 23.96%.A perovskite mini-module(5×5 cm^(2) with an active area of 14.28 cm^(2))could also be fabricated to achieve a PCE of 23.19%,ranking it among the highest for inverted PSMs.Additionally,the device could retain over 93% of its initial efficiency after MPP tracking at 45℃ for 1280 h.This study successfully demonstrates a bilayer interface engineering with respective functions,offering valuable insights for producing efficient and stable large-area PSCs.
文摘Photovoltaics,as a green technology for converting solar energy into electricity,have shown great promise to address the energy and environmental challenges for the sustainability of human society.In recent years,two types of photovoltaics,consisting of organic semiconductors or perovskites as light absorbers,have experienced a rapid development.The development of organic solar cells(OSC)can be dated back to 1986,since the discovery of a bi layer OSC by Di.C.W.Tang.Nowadays,OSCs made with polymer donors and small molecule acceptors have surpassed power conversion efficiencies(PCEs)of 16%for single-junction and 17%for tandem devices,through integrated innovative efforts on materials,interfaces,and device architectures.
基金A.K.Y.J.thanks the sponsorship of the Lee Shau-Kee Chair Professor(Materials Science)the support from the APRC Grant of the City University of Hong Kong(9380086)+3 种基金Innovation and Technology Fund(ITS/497/18FP,GHP/021/18SZ)the US Office of Naval Research(N00014-20-1-2191)the GRF grant(11307621)from the Research Grants Council of Hong Kong,Guangdong Major Project of Basic and Applied Basic Research(2019B030302007)the Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials(2019B121205002).
文摘CONSPECTUS:Along with the rapid industrialization of human society over the past century,incessant energy consumption and endless damage to the environment have aroused growing attention for seeking clean and renewable energy sources.Photovoltaics(PV)that can directly harvest and transform sunlight into electricity have shown great potential in achieving this goal.Especially for solution-processed thin-film solar cells,their extremely cost-effective and facile processing methods compatible with different substrates at large scales exhibit unique advantages over conventional PVs based on crystalline silicon.Various types of solutionprocessed thin-film PVs have been achieving or already exceeded 15%power conversion efficiency(PCE)through the numerous efforts of researchers.Organic solar cells(OSCs)and organic−inorganic hybrid perovskite solar cells(PVSCs)are the most well-known emerging solution-processed thin-film solar cells that have attracted great interest recently(the PCE of PVSCs soared form 3.8%to over 25%in the past decade).Usually,photogenerated excitons will form as a response to illumination in the active layer,then dissociate into charge carriers,travel in between layers,and finally get collected by electrodes of the device.Besides the broad exploration of active layer materials,suitably matched charge-transporting layers and electrodes also play a vital role in achieving high PCE and stability in PV devices.Furthermore,interfaces between different functional layers created during solution processing need to be carefully addressed to ensure efficient charge transport and prevent degradation.The utilization of proper interfacial materials to modify the chemical and electrical properties at interfaces has become an effective strategy to enhance the performance of PV.Therefore,it is important to develop a comprehensive understanding into the correlation between interfacial properties and charge carrier dynamics and establish molecular design principles for interfacial materials to realize commercialization of emerging PVs.
基金the financial support from the Scientific Research Project of Education Department of Hunan Province(21C0091)the Open Fund of the State Key Laboratory of Luminescent Materials and Devices(South China University of Technology)(2023skllmd-13)+6 种基金the support from the National Natural Science Foundation of China(22209131,22005121)the open fund support from School of Materials Science and Engineering,Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications(GDRGCS2021002,GDRGCS2022003,GDRGCS2022002)the support from the National Key Research and Development Program of China(2022YFE0132400)the National Natural Science Foundation of China(21875182,52173023)the Key Scientific and Technological Innovation Team Project of Shaanxi Province(2020TD-002)111 Project 2.0(BP0618008)supported by the Director,Office of Science,Office of Basic Energy Sciences,of the U.S.Department of Energy(DE-AC0205CH11231)。
文摘Additives play a crucial role in enhancing the photovoltaic performance of polymer solar cells(PSCs).However,the typical additives used to optimize blend morphology of PSCs are still high boiling-point solvents,while their trace residues may reduce device stability.Herein,an effective strategy of“solidification of solvent additive(SSA)”has been developed to convert additive from liquid to solid,by introducing a covalent bond into low-cost solvent diphenyl sulfide(DPS)to synthesize solid dibenzothiophene(DBT)in one-step,which achieves optimized morphology thus promoting efficiency and device stability.Owing to the fine planarity and volatilization of DBT,the DBT-processed films achieve ordered molecular crystallinity and suitable phase separation compared to the additive-free or DPS-treated ones.Importantly,the DBT-processed device also possesses improved light absorption,enhanced charge transport,and thus a champion efficiency of 17.9%is achieved in the PM6:Y6-based PSCs with an excellent additive component tolerance,reproducibility,and stability.Additionally,the DBT-processed PM6:L8-BO-based PSCs are further fabricated to study the universality of SSA strategy,offering an impressive efficiency approaching19%as one of the highest values in binary PSCs.In conclusion,this article developed a promising strategy named SSA to boost efficiency and improve stability of PSCs.
基金supported by the Fundamental Research Funds for the Central Universities(2021YJS176)the National Natural Science Foundation of China(61975006,62075155,62175011)+1 种基金the Postdoctoral Innovative Talent Support Program(BX20200042)the China Postdoctoral Science Foundation(2020M680327)。
文摘Photomultiplication-type polymer photodetectors(PM-PPDs)were achieved with polymer P3HT as donor and PY3Se-1V as acceptor based on structure of ITO/PEDOT:PSS/active layer/Al.The optimal weight ratio of P3HT to PY3Se-1V is about 100:3.Amounts of isolated electron traps are formed with PY3Se-1V surrounded by P3HT due to rather less content of PY3Se-1V in active layers and about 0.94 e V energy offset between the lowest unoccupied molecular orbitals(LUMO)of P3HT and PY3Se-1V.The optimal PM-PPDs exhibit broad spectral response from 350 to 950 nm and external quantum efficiency(EQE)values of68,200%at 360 nm,26,400%at 630 nm and 19,500%at 850 nm under-15 V bias.The working mechanism of PM-PPDs is attributed to the interfacial trap-assisted hole tunneling injection from external circuit.The performance of PM-PPDs can be further improved by incorporating appropriate PMBBDT with high hole mobility as the third component.The EQE values of optimal ternary PM-PPDs are increased to 105,000%at 360 nm,40,000%at 630 nm and 31,800%at 850 nm under-15 V bias,benefiting from the enhanced hole transport in ternary active layers.The optimal ternary PM-PPDs were successfully applied in a light-controlled circuit to turn on or turn off light emitting diode(LED).
基金supported by the National Natural Science Foundation of China(21704082,21875182,22209131)the Key Scientific and Technological Innovation Team Project of Shaanxi Province(2020TD-002)111 Project 2.0(BP2018008).
文摘Before 2015,only few organic solar cells(OSCs)obtained power conversion efficiencies(PCEs)over 10%because the commonly used fullerene derivatives as acceptors have narrow absorption,low extinction coefficient,and are difficult to adjust energy levels.To overcome these shortcomings,in 2015,Zhan et al.[1]developed acceptor(A)-donor(D)-A-type fused-ring small-molecule acceptors(SMAs)with good planarity and strong intramolecular charge transfer(ICT)effect to fulfill both broad absorption and high extinction coefficient,offering the revolutionary PCEs of 13%–15%.In 2019,another milestone SMA(Y6)with A-DA′D-A structure was developed by Zou et al.
基金support from the National Science Foundation(nos.62275076,92163135,and 11904098)the Shanghai Pilot Program for Basic Research(22JC1403200)+9 种基金sponsorship of the Lee Shau-Kee Chair Professor(Materials Science)the support from the APRC Grant of the City University of Hong Kong(9380086)the TCFS grant(GHP/018/20SZ)and theMRP grant(MRP/040/21X)from the Innovation and Technology Commission of Hong Kongthe Green Tech Fund from the Environment and Ecology Bureau of Hong Kong(202020164)GRF grants from the Research Grants Council of Hong Kong(11307621 and 11316422)Shenzhen Science and Technology Program(SGDX20201103095412040)Guangdong Major Project of Basic and Applied Basic Research(2019B030302007)Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic,Magnetic Functional Materials(2019B121205002)the US Office of Naval Research(N00014-20-1-2191)the CRF grant fromthe ResearchGrants Council of Hong Kong(C6023-19GF).
文摘Since human society has been rapidly industrializing over the past century,excessive energy consumption and environmental damage have raised awareness of the need for clean,renewable energy sources.Especially after the outbreak of the Russian-Ukrainian war,the development of alternative energy issue has been elevated to an unprecedented strategic level.Solar energy,as one of the clean and renewable energies,is experiencing a historical stage of changing its role from supplementary energy to alternative energy.The exploration of photovoltaic(PV)cells with newmaterials and structures is urgent tomeet the demand of achieving carbon-peak and carbon-neutralization goals.
基金City University of Hong Kong,Grant/Award Number:9380086Innovation and Technology Commission of Hong Kong,Grant/Award Numbers:GHP/018/20SZ,MRP/040/21X+3 种基金Environment and Ecology Bureau of Hong Kong,Grant/Award Number:202020164Research Grants Council of Hong Kong,Grant/Award Numbers:11307621,C6023-19GFShenzhen Science and Technology Program,Grant/Award Number:SGDX20201103095412040Guangdong Major Project of Basic and Applied Basic Research,Grant/Award Number:2019B030302007。
文摘Organic photovoltaics(OPVs)represent one of the most promising photovoltaic technologies owing to their high capacity to convert solar energy to electricity.With the continuous structure upgradation of photovoltaic materials,especially that of non-fullerene acceptors(NFAs),the OPV field has witnessed rapid progress with power conversion efficiency(PCE)exceeding 19%.However,it remains challenging to overcome the intrinsic trade-off between the photocurrent and photovoltage,restricting the further promotion of the OPV efficiency.In this regard,it is urgent to further tailor the structure of NFAs to broaden their absorption spectra while mitigating the energy loss of relevant devices concomitantly.Heteroatom substitution on the fused-ringπ-core of NFAs is an efficient way to achieve this goal.In addition to improve the nearinfrared light harvest by strengthening the intramolecular charge transfer,it can also enhance the molecular stacking via forming multiple noncovalent interactions,which is favorable for reducing the energetic disorder.Therefore,in this review we focus on the design rules of NFAs,including the polymerized NFAs,of which the core moiety is substituted by various kinds of heteroatoms.We also afford a comprehensive understanding on the structure–propertyperformance relationships of these NFAs.Finally,we anticipate the challenges restricting the efficiency promotion and industrial utilization of OPV,and provide potential solutions based on the further heteroatom optimization on NFA core-moiety.
