Numerous fabrication methods have been developed for high-efficiency perovskite solar cells(PSCs). However, these are limited to spin-coating processes in a glove box and are yet to be commercialized. Therefore, there...Numerous fabrication methods have been developed for high-efficiency perovskite solar cells(PSCs). However, these are limited to spin-coating processes in a glove box and are yet to be commercialized. Therefore, there is a need to develop a controllable and scalable deposition technique that can be carried out under ambient conditions. Even though the doctor-blade coating technique has been widely used to prepare PSCs, it is yet to be applied to high-efficiency PSCs under ambient conditions(RH ~45%, RT ~25 °C). In this study, we conducted blade-coating fabrication of modified high-efficiency PSCs under such conditions. We controlled the substrate temperature to ensure phase transition of perovskite and added dimethyl sulfoxide(DMSO) to the perovskite precursor solution to delay crystallization, which can facilitate the formation of uniform perovskite films by doctor-blade coating. The as-prepared perovskite films had large crystal domains measuring up to 100 μm. Solar cells prepared from these films exhibited a current density that was enhanced from 17.22 to 19.98 m A/cm^2 and an efficiency that was increased from 10.98% to 13.83%. However, the open-circuit voltage was only 0.908 V, probably due to issues with the hole-transporting layer. Subsequently, we replaced poly(3,4-ethylenedioxythiophene) polystyrene sulfonate(PEDOT:PSS) with Ni O x as the hole-transporting material and then prepared higher-quality perovskite films by blade-coating under ambient conditions. The as-prepared perovskite films were preferably orientated and had large crystal domains measuring up to 200 μm;The open-circuit voltage of the resulting PSCs was enhanced from 0.908 to 1.123 V, while the efficiency increased from 13.83% to 15.34%.展开更多
Two extended hybrid conjugated systems based on a triphenylamine(TPA) core with two and three peripheral 1,4-dithiafulvenes(DTF) units coded WH-2 and WH-3 as hole-transporting materials(HTMs) applied in perovskite sol...Two extended hybrid conjugated systems based on a triphenylamine(TPA) core with two and three peripheral 1,4-dithiafulvenes(DTF) units coded WH-2 and WH-3 as hole-transporting materials(HTMs) applied in perovskite solar cells(PSCs) are synthesized by facile one-step reaction in good yield over 75%. DTF unit as electron donor can enhance the electron donating ability and the fusion of benzenic ring of TPA with DTF unit may lead to reinforced intermolecular interactions in the solid state. In addition,WH-2 and WH-3 exhibit a pyramid shape containing partial planarity and quasi three-dimensionality features, which is also conducive to enhancing the π-π stacking of molecules in the solid state. The above-mentioned structural characteristics make the two HTMs have good hole mobilities. As a result,WH-2 and WH-3 obtained the high intrinsic hole mobilities of 4.69 × 10^(-4)and 2.18 × 10^(-3)cm^(2)V^(-1)s^(-1)respectively. Finally, the power conversion efficiencies(PCEs) of PSCs with WH-2 and WH-3 as cost-effective dopant-free HTMs are 15.39% and 19.22% respectively and the PCE of PSC with WH-3 is on a par with that of PSC with Li-TFSI/t-BP doped Spiro-OMe TAD(19.67%).展开更多
Organic π-functional molecules are the foundation and basic component of organic optoelectronic devices.For example,for ideal carrier transporting materials,extended π-conjugation and ordered π-πstacking are neces...Organic π-functional molecules are the foundation and basic component of organic optoelectronic devices.For example,for ideal carrier transporting materials,extended π-conjugation and ordered π-πstacking are necessary to enhance the charge mobility and achieve desirable results.As a promising way to convert sunlight into electricity,organometal halide perovskite solar cells（PSCs） have captured a lot of attention due to its predominant merits especially in the aspect of remarkable photovoltaic performance and much potentially low production cost.For conventional planar PSC structure,hole-transporting layer which typically consists of organic π-functional materials plays a key role in suppressing holeelectron pair recombination,promoting charge transporting and ensuring ohmic contact of back electrode.Considering the key roles of HTMs and its soaring progress in recent years,here,we will summarize recent progress in small organic π-functional materials from its diverse functions in PSCs.Besides,aiming to further promote the development of organic π-functional molecules and HTMs,a promising direction toward highly efficient HTMs will also be discussed.展开更多
Hole-transporting materials play a vital role in terms of the performance of perovskite solar cells(PSCs).The dithieno[3,2-b:2’,3’-d]pyrrole(DTP),an S,N-heterocyclic building block,has been proved to be desirable fo...Hole-transporting materials play a vital role in terms of the performance of perovskite solar cells(PSCs).The dithieno[3,2-b:2’,3’-d]pyrrole(DTP),an S,N-heterocyclic building block,has been proved to be desirable for molecular design of hole-transporting materials in PSCs.We developed an asymmetrically substituted DTP small-molecule(JW12)and a reference compound(JW11).The asymmetrical structure of JW12 leads to different absorption properties and electron distribution.The device in a planar n-i-p architecture using JW12 shows a much higher PCE(18.07%)than that based on JW11(15.46%),which is also better than the device based on spiro-OMe TAD(17.47%).We hope our research can provide a new perspective in molecular design of organic HTMs for perovskite solar cells.展开更多
In order to improve the efficiency and stability of inverted three-dimensional(3D) or quasi-2D perovskite solar cells(PSCs) for future commercialization, exploring high efficient dopant-free polymer holetransporting m...In order to improve the efficiency and stability of inverted three-dimensional(3D) or quasi-2D perovskite solar cells(PSCs) for future commercialization, exploring high efficient dopant-free polymer holetransporting materials(HTMs) is still desired and meaningful. One simple and efficient way to achieve high performance dopant-free HTMs is to synthesize novel non-conjugated side-chain polymers via rational molecular design. In this work, N-(4-methoxyphenyl)-9,9-dimethyl-9H-fluoren-2-amine(FMeNPh) groups are introduced into the poly(N-vinylcarbazole)(PVK) side chains to afford two nonconjugated polymers PVCz-DFMeNPh and PVCz-FMeNPh as dopant-free HTMs in inverted quasi-2D PSCs. Benefited from the flexible properties of polyethylene backbone and excellent optoelectronic natures of FMeNPh side-chain groups, PVCz-DFMeNPh with more FMeNPh units exhibited excellent thermal stability, well-matched energy levels and improved charge mobility as compared to PTAA and PVCzFMeNPh. Moreover, the morphologies investigation of quasi-2D perovskite on PVCz-DFMeNPh shows more compact and homogeneous perovskite films than those on PTAA and PVCz-FMeNPh. As a result,the dopant-free PVCz-DFMeNPh based inverted quasi-2D PSCs deliver power conversion efficiency(PCE) up to 18.44% as well as negligible hysteresis and favorable long-term stability, which represents as excellent performance reported to date for inverted quasi-2D PSCs. The results demonstrate the great potentials of constructing non-conjugated side-chain polymer HTMs based on phenylfluorenamine-func tionalized PVK for the development of high efficient and stable inverted 3D or quasi-2D PSCs.展开更多
Two hole-transporting materials containing carbazole moieties with TPD- and NPB-like structures, 4,4′-bis [ N- （4-carbazolylphenyl） -N-phenylamino ] biphenyl （ CPB ） and 4,4′-bis [ N- （ 4-carbazolylphenyl ） -...Two hole-transporting materials containing carbazole moieties with TPD- and NPB-like structures, 4,4′-bis [ N- （4-carbazolylphenyl） -N-phenylamino ] biphenyl （ CPB ） and 4,4′-bis [ N- （ 4-carbazolylphenyl ） -N- （ 1-naphthyl ） amino] biphenyl（ CNB）, were synthesized via a modified Ullmann reaction. The resulting compounds were thermally stable with high glass transition temperatures ranging from 145 to 147 ℃ and possessed a good electrochemical reversibility and hole-transporting properties. Typical double-layer device evaluation with the structure ITO/CPB（40 nm）/ Alq3 （60 nm）/LiF/Al demonstrated that they were promising hole-transporting materials with a current efficiency of 5.25 cd/A and a power efficiency of 2.00 lm/W.展开更多
Perovskite solar cells(PVSCs)have emerged as a promising photovoltaic technology and have attracted wide research interest due to their outstanding photovoltaic performance,low cost,and the ability to fabricate largea...Perovskite solar cells(PVSCs)have emerged as a promising photovoltaic technology and have attracted wide research interest due to their outstanding photovoltaic performance,low cost,and the ability to fabricate largearea devices.An impressive certified power conversion efficiency(PCE)of 25.2%has been achieved,demonstrating the excellent potential of PVSCs for future applications.Hole-transporting materials play a key role in improving the device performance of PVSCs by facilitating the extraction of photogenerated holes and their transport from the perovskite layer to the anode.This review provides a brief introduction to PVSCs and summarizes the recent progress in small molecule hole-transporting materials(SM-HTMs)bearing various cores and different4-anisylamino-based end caps.We classify the end caps into N,N-di-4-anisylamino(DAA),4-(N,N-di-4-anisylamino)benzo(DAB),and N3,N6(or N2,N7)-bis(di-4-anisylamino)-9 H-carbazole(3,6-DAC or 2,7-DAC)groups.We also review the core type,end cap position and number,how these affect the overall properties of the SM-HTMs,and the resultant PVSC device performances.Finally,the challenges and perspectives for the future development of SM-HTMs are presented.展开更多
Two novel organic hole-transporting materials have been synthesized by combination of triphenylamines（TPA） viaπ-conjugated bonds using Wittig reaction.The structures were characterized by NMR,FT-IR and HRMS.The opt...Two novel organic hole-transporting materials have been synthesized by combination of triphenylamines（TPA） viaπ-conjugated bonds using Wittig reaction.The structures were characterized by NMR,FT-IR and HRMS.The optical,electrochemical and thermal properties of the materials were studied in detail.The results show that these two compounds have blue emission,proper HOMO levels and high thermal stability.Furthermore,a quantum chemical calculation on electron distribution of the two compounds was performed, which suggests the current synthesized materials would be promising candidates for hole-transporting materials.展开更多
Three star-shaped truxene-based small molecules（namely TXH,TXM,TXO） were synthesized,characterized and used as hole-transporting materials（HTMs） for perovskite solar cells（Pv SCs）. The device based on TXO delive...Three star-shaped truxene-based small molecules（namely TXH,TXM,TXO） were synthesized,characterized and used as hole-transporting materials（HTMs） for perovskite solar cells（Pv SCs）. The device based on TXO delivered a respectable power conversion efficiency（PCE） of 7.89% and a high open-circuit voltage（Voc） of 0.97 V,which far exceeded the values of the devices based on other two small molecules. The highest PCE for the device based on TXO is mainly contributed from its lowest series resistance（Rs） value and largest short-circuit current（Jsc） value under the same circumstances. All these results indicate that TXO is a promising HTM candidate for Pv SCs.展开更多
We present a systematic analysis of the exciton-recombination zone within all-quantum-dot （QD） multilayer films using sensing QD layers in QD-based light-emitting diodes （QLEDs）, and demonstrate the a11-QD multila...We present a systematic analysis of the exciton-recombination zone within all-quantum-dot （QD） multilayer films using sensing QD layers in QD-based light-emitting diodes （QLEDs）, and demonstrate the a11-QD multilayer films with different sequences of layers prepared by inserting a sensing blue QD layer denoted as B at various positions within four red QD multilayers denoted as R. We also use different hole transporting layers （PVK, CBP as well as poly-TPD） to prevent the formation of leakage current and to improve the luminance. The results show that the total EL emission is mostly at the fourth （60%） and fifth （40%） QD monolayers, adjacent to ITO. This presents both decreasing current density and increasing brightness with different hole transporting layers, thus resulting in more efficient performance.展开更多
Two electron-rich,solution-processable phenonaphthazine derivatives,5,12-bis(N-[4,4'-bis-(phenyl)aminophen-4''-yi])-phenonaphthazine(BPZTPA)and 5,12-bis(N-[4,4'-bis(methoxy-phenyl)aminophen-4''...Two electron-rich,solution-processable phenonaphthazine derivatives,5,12-bis(N-[4,4'-bis-(phenyl)aminophen-4''-yi])-phenonaphthazine(BPZTPA)and 5,12-bis(N-[4,4'-bis(methoxy-phenyl)aminophen-4''-yl])-phenonaphthazine(MeO-BPZTPA)have been designed and employed in the fabrication of perovskite solar cells.BPZTPA and MeO-BPZTPA exhibit excellent thermal stabilities,hole mobilities(similar to 10^(-4)cm^(2)/(V.s))and suitable HOMO levels(-5.34 and-5.29 eV,respectively)relative to the valence band of the CH3NH3PbI3 and Au work function,showing their potential as alternative hole-transporting materials(HTMs).Meanwhile,the corresponding mesoporous TiO_(2)/CH_(3)NH_(3)PbI_(3)/HTM/Au devices are investigated,and the best power conversion efficiency of 10.36%has been achieved for MeO-BPZTPA without using p-type dopant.(C)2016 Science Press and Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.and Science Press.All rights reserved.展开更多
In this work, a comprehensive study on the deliberate molecular design and modifications of electron donors is carried out to elucidate correlations between the methoxy effects and donor configuration of hole-transpor...In this work, a comprehensive study on the deliberate molecular design and modifications of electron donors is carried out to elucidate correlations between the methoxy effects and donor configuration of hole-transporting materials(HTMs). Our initial findings demonstrate the donor-dependent methoxy effects. Photovoltaic performance of the HTM with twisted donor highly depends on the methoxy substituent. In contrast, efficiency’s reliance on methoxy is insignificant for the HTM with planar donor. The HTM(M123) featuring the methoxy–substituted carbazole shows a decent power conversion efficiency of 19.33% due to synergistic effects from both planar structure and methoxy. This work gives a guideline to access HTMs reaching both high-performance and good stability.展开更多
During the last decade,perovskite solar technologies underwent an impressive development,with power conversion efficiencies reaching 25.5%for single-junction devices and 29.8%for Silicon-Perovskite tandem configuratio...During the last decade,perovskite solar technologies underwent an impressive development,with power conversion efficiencies reaching 25.5%for single-junction devices and 29.8%for Silicon-Perovskite tandem configurations.Even though research mainly focused on improving the efficiency of perovskite photovoltaics(PV),stability and scalability remain fundamental aspects of a mature photovoltaics technology.For n-i-p structure perovskite solar cells,using poly-triaryl(amine)(PTAA)as hole transport layer(HTL)allowed to achieve marked improvements in device stability compared with other common hole conductors.For p-i-n structure,poly-triaryl(amine)is also routinely used as dopant-free hole transport layer,but problems in perovskite film growth,and its limited resistance to stress and imperfect batch-to-batch reproducibility,hamper its use for device upscaling.Following previous computational investigations,in this work,we report the synthesis of two small-molecule organic hole transport layers(BPT-1,2),aiming to solve the above-mentioned issues and allow upscale to the module level.By using BPT-1 and methylammonium-free perovskite,max.Power conversion efficiencies of 17.26%and 15.42%on a small area(0.09 cm^(2))and mini-module size(2.25 cm^(2)),respectively,were obtained,with a better reproducibility than with poly-triaryl(amine).Moreover,BPT-1 was demonstrated to yield more stable devices compared with poly-triaryl(amine)under ISOS-D1,T1,and L1 accelerated life-test protocols,reaching maximum T_(90)values>1000 h on all tests.展开更多
Carbazole-based self-assembled molecules have been widely adopted as hole-transporting layers(HTLs)in high-performance organic solar cells(OSCs).However,their practical implementation has been constrained by their lim...Carbazole-based self-assembled molecules have been widely adopted as hole-transporting layers(HTLs)in high-performance organic solar cells(OSCs).However,their practical implementation has been constrained by their limited concentration in solutions and poor solvent tolerance.Herein,to address these limitations,we designed two novel trimeric molecules(TPACz-1 and TPACz-2)that synergistically integrate the structural merits of small molecules with the processing advantages of polymers.Notably,TPACz-2 showed exceptional hole-transporting capacity with uniform coverage on indium tin oxide(ITO)substrates,coupled with robust processability characterized by an extended concentration tolerance range(0.2–1.0 mg mL^(-1))and compatibility with a broad range of solvents.Binary OSCs based on TPACz-2 showed an excellent power conversion efficiency(PCE)of 19.65%with a short-circuit current density of 27.49 mA cm^(-2)and a fill factor of 80.9%.At the same time,the corresponding ternary devices exhibited a high PCE exceeding 20%.Furthermore,the TPACz-based devices demonstrated superior ambient stability,retaining~80%of their initial PCE after 680 h at 25%relative humidity,substantially outperforming conventional PEDOT:PSS-based counterparts.This work offers valuable guidance and highlights the crucial role of oligomeric molecular design as a pivotal strategy for the development of innovative HTLs in OSCs.展开更多
A series of conductive polymers, i.e., poly（3-methylthiophene） （PMT）, poly（thiophene） （PT）, poly（3-bromothiophene） （PBT） and poly（3-chlorothiophene） （PCT）, were prepared via the electrochemical polymer...A series of conductive polymers, i.e., poly（3-methylthiophene） （PMT）, poly（thiophene） （PT）, poly（3-bromothiophene） （PBT） and poly（3-chlorothiophene） （PCT）, were prepared via the electrochemical polymerization process. Subse- quently, their application as hole-transporting materials （HTMs） in CHBNI-I3Pb｜3 perovskite solar cells was explored. It was found that rationally increasing the work function of HTMs proves beneficial in improving the open circuit voltage （Voc） of the devices with an ITO/conductive-polymer/CHBNHBPbIg/C60/BCP/Ag structure. In addition, the higher-Voc devices with a higher-work-function HTM exhibited higher recombination resistances. The highest open circuit voltage of 1.04 V was obtained from devices with PCT, with a work function of -5.4 eV, as the hole-transporting layer. Its power conversion efficiency attained a value of approximately 16.5%, with a high fill factor of 0.764, an appreciable open voltage of 1.01 V and a short circuit current density of 21.4 mA.cm-2. This simple, controllable and low-cost manner of preparing HTMs will be beneficial to the production of large-area perovskite solar cells with a hole-transportin~ laver.展开更多
Ultrathin polythiophene films prepared via electrochemical polymerization is successfully used as the hole-transporting material, substituting conventional HTM-PEDOT：PSS, in planar p-i-n CH3NH3PbI3 perovskite-based s...Ultrathin polythiophene films prepared via electrochemical polymerization is successfully used as the hole-transporting material, substituting conventional HTM-PEDOT：PSS, in planar p-i-n CH3NH3PbI3 perovskite-based solar cells, affording a series of ITO/polythiophene/CH3NHBPbIB/C60/BCP/Ag devices. The ultrathin polythiophene film possesses good transmittance, high conductivity, a smooth surface, high wettability, compatibility with PbI2 DMF solution, and an energy level matching that of the CH3NH3PbI3 perovskite material. A promising power conversion efficiency of about 15.4%, featuring a high fill factor of 0.774, open voltage of 0.99 V, and short-circuit current density of 20.3 mA·cm^-2 is obtained. The overall performance of the devices is superior to that of cells using PEDOT：PSS. The differences of solar cells with different hole-transfer materials in charge recombination, charge transport and transfer, and device stability are further investigated and demonstrate that polythiophene is a more effective and promising hole-transporting material. This work provides a simple, prompt, controllable, and economic approach for the preparation of an effective hole-transporting material, which undoubtedly offers an alternative method in the future industrial production of perovskite solar cells.展开更多
Organic polymer solar cells （OSCs） and organic-inorganic hybrid perovskite solar cells （PSCs） have achieved notable progress over the past several years. A central topic in these fields is exploring electronically...Organic polymer solar cells （OSCs） and organic-inorganic hybrid perovskite solar cells （PSCs） have achieved notable progress over the past several years. A central topic in these fields is exploring electronically efficient, stable and effective hole-transporting layer （HTL） materials. The goal is to enhance hole-collection ability, reduce charge recombination, increase built-in voltage, and hence improve the performance as well as the device stability. Transition metal oxides （TMOs） semiconductors such as NiOx, CuOx, CrOx, MoOx, WO3, and V2O5, have been widely used as HTLs in OSCs. These TMOs are naturally adopted into PSC as HTLs and shows their importance. There are similarities, and also differences in applying TMOs in these two types of main solution processed solar cells. This concise review is on the recent developments of transition metal oxide HTL in OSCs and PSCs. The paper starts from the discussion of the cation valence and electronic structure of the transition metal oxide materials, followed by analyzing the structure-property relationships of these HTLs, which we attempt to give a systematic introduction about the influences of their cation valence, electronic structure, work ftmction and film property on device performance.展开更多
The development of alternative low-cost and high-performing hole-transporting materials(HTMs) is of great significance for the potential large-scale application of perovskite solar cells(PSCs) in the future.Here,a fac...The development of alternative low-cost and high-performing hole-transporting materials(HTMs) is of great significance for the potential large-scale application of perovskite solar cells(PSCs) in the future.Here,a facilely synthesized solution-processable copper tetra-(2,4-dimethyl-3-pentoxy) phthalocyanine(CuPc-DMP) via only two simple steps,has been incorporated as a hole-transporting material(HTM) in mesoscopic perovskite solar cells(PSCs).The optimized devices based on such a HTM afford a very competitive power conversion efficiency(PCE) of up to 17.1%measured at 100 mW cm^(-2) AM 1.5G irradiation,which is on par with that of the well-known 2,2',7,7'-tetrakis(N'N'-di-p-methoxyphenylamine)-9,9'-spirobifluorene(spiro-OMeTAD)(16.7%) under equivalent conditions.This is,to the best of our knowledge,the highest value reported so far for metal organic complex-based HTMs in PSCs.The advantages of this HTM observed,such as facile synthetic procedure,superior hole transport characteristic,high photovoltaic performance together with the feasibility of tailoring the molecular structure would make solution-processable copper phthalocyanines as a class of promising HTM that can be further explored in PSCs.The present finding highlights the potential application of solution processed metal organic complexes as HTMs for cost-effective and high-performing PSCs.展开更多
Quantum-dot light-emitting diodes(QLEDs)are multilayer electroluminescent devices promising for next-generation display and solid-state-lighting technologies.In the state-of-the-art QLEDs,hole-injection layers(HILs)wi...Quantum-dot light-emitting diodes(QLEDs)are multilayer electroluminescent devices promising for next-generation display and solid-state-lighting technologies.In the state-of-the-art QLEDs,hole-injection layers(HILs)with high work functions are generally used to achieve efficient hole injection.In these devices,Fermi-level pinning,a phenomenon often observed in heterojunctions involving organic semiconductors,can take place in the hole-injection/hole-transporting interfaces.However,an in-depth understanding of the impacts of Fermi-level pinning at the hole-injection/hole-transporting interfaces on the operation and performance of QLEDs is still lacking.Here,we develop a set of NiOx HILs with controlled work functions of 5.2–5.9 eV to investigate QLEDs with Fermi-level pinning at the hole-injection/hole-transporting interfaces.The results show that despite that Fermi-level pinning induces identical apparent hole-injection barriers,the red QLEDs using HILs with higher work functions show improved efficiency roll-off and better operational stability.Remarkably,the devices using the NiOx HILs with a work function of 5.9 eV demonstrate a peak external quantum efficiency of~18.0%and a long T95 operational lifetime of 8,800 h at 1,000 cd·m^(−2),representing the best-performing QLEDs with inorganic HILs.Our work provides a key design principle for future developments of the hole-injection/hole-transporting interfaces of QLEDs.展开更多
The development of an efficient, stable, and low-cost hole-transporting material (HTM) is of great significance for perovskite solar cells (PSCs) from future commercialization point of view. Herein, we specifically sy...The development of an efficient, stable, and low-cost hole-transporting material (HTM) is of great significance for perovskite solar cells (PSCs) from future commercialization point of view. Herein, we specifically synthesize a dicationic salt of X60 termed X60(TFSI)2, and adopt it as an effective and stable "doping" agent to replace the previously used lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) for the low-cost organic HTM X60 in PSCs. The incorporation of this dicationic salt significantly increases the hole conductivity of X60 by two orders of magnitude from 10-6 to 10-4 S cm-1. The dramatic enhancement of the conductivity leads to an impressive power conversion efficiency (PCE) of 19.0% measured at 1 sun illumination (100 mW cm-2, AM 1.5 G), which is comparable to that of the device doped with LiTFSI (19.3%) under an identical condition. More strikingly, by replacing LiTFSI, the PSC devices incorporating X60(TFSI)2 also show an excellent long-term durability under ambient atmosphere for 30 days, mainly due to the hydrophobic nature of the X60(TFSI)2 doped HTM layer,which can effectively prevent the moisture destroying the perovskite layer. The present work paves the way for the development of highly efficient, stable, and low-cost HTM for potential commercialization of PSCs.展开更多
基金supported by the National Key Research and Development Project funding from the Ministry of Science and Technology of China (Grants Nos. 2016YFA0202400 and 2016YFA0202404)the Peacock Team Project funding from Shenzhen Science and Technology Innovation Committee (Grant No. KQTD2015033110182370)+1 种基金the Fundamental Research (Discipline Arrangement) Project funding from Shenzhen Science and Technology Innovation Committee (Grant No. JCYJ20170412154554048)the National Natural Science Foundation of China (Grant No. 51473139)
文摘Numerous fabrication methods have been developed for high-efficiency perovskite solar cells(PSCs). However, these are limited to spin-coating processes in a glove box and are yet to be commercialized. Therefore, there is a need to develop a controllable and scalable deposition technique that can be carried out under ambient conditions. Even though the doctor-blade coating technique has been widely used to prepare PSCs, it is yet to be applied to high-efficiency PSCs under ambient conditions(RH ~45%, RT ~25 °C). In this study, we conducted blade-coating fabrication of modified high-efficiency PSCs under such conditions. We controlled the substrate temperature to ensure phase transition of perovskite and added dimethyl sulfoxide(DMSO) to the perovskite precursor solution to delay crystallization, which can facilitate the formation of uniform perovskite films by doctor-blade coating. The as-prepared perovskite films had large crystal domains measuring up to 100 μm. Solar cells prepared from these films exhibited a current density that was enhanced from 17.22 to 19.98 m A/cm^2 and an efficiency that was increased from 10.98% to 13.83%. However, the open-circuit voltage was only 0.908 V, probably due to issues with the hole-transporting layer. Subsequently, we replaced poly(3,4-ethylenedioxythiophene) polystyrene sulfonate(PEDOT:PSS) with Ni O x as the hole-transporting material and then prepared higher-quality perovskite films by blade-coating under ambient conditions. The as-prepared perovskite films were preferably orientated and had large crystal domains measuring up to 200 μm;The open-circuit voltage of the resulting PSCs was enhanced from 0.908 to 1.123 V, while the efficiency increased from 13.83% to 15.34%.
基金the Sichuan Science and Technology Program (2019YJ0162)the National Natural Science Foundation of China (21402023, 51773027)the National Key R@D Program of China (2017YFB0702802) for financial support。
文摘Two extended hybrid conjugated systems based on a triphenylamine(TPA) core with two and three peripheral 1,4-dithiafulvenes(DTF) units coded WH-2 and WH-3 as hole-transporting materials(HTMs) applied in perovskite solar cells(PSCs) are synthesized by facile one-step reaction in good yield over 75%. DTF unit as electron donor can enhance the electron donating ability and the fusion of benzenic ring of TPA with DTF unit may lead to reinforced intermolecular interactions in the solid state. In addition,WH-2 and WH-3 exhibit a pyramid shape containing partial planarity and quasi three-dimensionality features, which is also conducive to enhancing the π-π stacking of molecules in the solid state. The above-mentioned structural characteristics make the two HTMs have good hole mobilities. As a result,WH-2 and WH-3 obtained the high intrinsic hole mobilities of 4.69 × 10^(-4)and 2.18 × 10^(-3)cm^(2)V^(-1)s^(-1)respectively. Finally, the power conversion efficiencies(PCEs) of PSCs with WH-2 and WH-3 as cost-effective dopant-free HTMs are 15.39% and 19.22% respectively and the PCE of PSC with WH-3 is on a par with that of PSC with Li-TFSI/t-BP doped Spiro-OMe TAD(19.67%).
基金the financial support from the National Natural Science Foundation of China(Nos.21572152 and 61575136)funded by Collaborative Innovation Center (CIC) of Suzhou Nano Science and Technologyby the Priority Academic Program Development of the Jiangsu Higher Education Institutions (PAPD)
文摘Organic π-functional molecules are the foundation and basic component of organic optoelectronic devices.For example,for ideal carrier transporting materials,extended π-conjugation and ordered π-πstacking are necessary to enhance the charge mobility and achieve desirable results.As a promising way to convert sunlight into electricity,organometal halide perovskite solar cells（PSCs） have captured a lot of attention due to its predominant merits especially in the aspect of remarkable photovoltaic performance and much potentially low production cost.For conventional planar PSC structure,hole-transporting layer which typically consists of organic π-functional materials plays a key role in suppressing holeelectron pair recombination,promoting charge transporting and ensuring ohmic contact of back electrode.Considering the key roles of HTMs and its soaring progress in recent years,here,we will summarize recent progress in small organic π-functional materials from its diverse functions in PSCs.Besides,aiming to further promote the development of organic π-functional molecules and HTMs,a promising direction toward highly efficient HTMs will also be discussed.
基金supported by the Scientific Research Project of Tianjin Municipal Education Committee(2017KJ261)。
文摘Hole-transporting materials play a vital role in terms of the performance of perovskite solar cells(PSCs).The dithieno[3,2-b:2’,3’-d]pyrrole(DTP),an S,N-heterocyclic building block,has been proved to be desirable for molecular design of hole-transporting materials in PSCs.We developed an asymmetrically substituted DTP small-molecule(JW12)and a reference compound(JW11).The asymmetrical structure of JW12 leads to different absorption properties and electron distribution.The device in a planar n-i-p architecture using JW12 shows a much higher PCE(18.07%)than that based on JW11(15.46%),which is also better than the device based on spiro-OMe TAD(17.47%).We hope our research can provide a new perspective in molecular design of organic HTMs for perovskite solar cells.
基金financially supported by the National Key Research and Development Program of China (2018YFB0406704)the National Natural Science Foundation of China (61974066, 61725502, 61634001)+3 种基金the Major Research Plan of the National Natural Science Foundation of China (91733302)the fund for Talented of Nanjing Tech University (201983)the Major Program of Natural Science Research of Jiangsu Higher Education Institutions of China (18KJA510002)the Synergetic Innovation Center for Organic Electronics and Information Displays。
文摘In order to improve the efficiency and stability of inverted three-dimensional(3D) or quasi-2D perovskite solar cells(PSCs) for future commercialization, exploring high efficient dopant-free polymer holetransporting materials(HTMs) is still desired and meaningful. One simple and efficient way to achieve high performance dopant-free HTMs is to synthesize novel non-conjugated side-chain polymers via rational molecular design. In this work, N-(4-methoxyphenyl)-9,9-dimethyl-9H-fluoren-2-amine(FMeNPh) groups are introduced into the poly(N-vinylcarbazole)(PVK) side chains to afford two nonconjugated polymers PVCz-DFMeNPh and PVCz-FMeNPh as dopant-free HTMs in inverted quasi-2D PSCs. Benefited from the flexible properties of polyethylene backbone and excellent optoelectronic natures of FMeNPh side-chain groups, PVCz-DFMeNPh with more FMeNPh units exhibited excellent thermal stability, well-matched energy levels and improved charge mobility as compared to PTAA and PVCzFMeNPh. Moreover, the morphologies investigation of quasi-2D perovskite on PVCz-DFMeNPh shows more compact and homogeneous perovskite films than those on PTAA and PVCz-FMeNPh. As a result,the dopant-free PVCz-DFMeNPh based inverted quasi-2D PSCs deliver power conversion efficiency(PCE) up to 18.44% as well as negligible hysteresis and favorable long-term stability, which represents as excellent performance reported to date for inverted quasi-2D PSCs. The results demonstrate the great potentials of constructing non-conjugated side-chain polymer HTMs based on phenylfluorenamine-func tionalized PVK for the development of high efficient and stable inverted 3D or quasi-2D PSCs.
文摘Two hole-transporting materials containing carbazole moieties with TPD- and NPB-like structures, 4,4′-bis [ N- （4-carbazolylphenyl） -N-phenylamino ] biphenyl （ CPB ） and 4,4′-bis [ N- （ 4-carbazolylphenyl ） -N- （ 1-naphthyl ） amino] biphenyl（ CNB）, were synthesized via a modified Ullmann reaction. The resulting compounds were thermally stable with high glass transition temperatures ranging from 145 to 147 ℃ and possessed a good electrochemical reversibility and hole-transporting properties. Typical double-layer device evaluation with the structure ITO/CPB（40 nm）/ Alq3 （60 nm）/LiF/Al demonstrated that they were promising hole-transporting materials with a current efficiency of 5.25 cd/A and a power efficiency of 2.00 lm/W.
基金the National Natural Science Foundation of China(NSFC,21825502)the Foundation of State Key Laboratory of Polymer Materials Engineering(SKLPME 2017-2-04)the Fundamental Research Funds for the Central Universities。
文摘Perovskite solar cells(PVSCs)have emerged as a promising photovoltaic technology and have attracted wide research interest due to their outstanding photovoltaic performance,low cost,and the ability to fabricate largearea devices.An impressive certified power conversion efficiency(PCE)of 25.2%has been achieved,demonstrating the excellent potential of PVSCs for future applications.Hole-transporting materials play a key role in improving the device performance of PVSCs by facilitating the extraction of photogenerated holes and their transport from the perovskite layer to the anode.This review provides a brief introduction to PVSCs and summarizes the recent progress in small molecule hole-transporting materials(SM-HTMs)bearing various cores and different4-anisylamino-based end caps.We classify the end caps into N,N-di-4-anisylamino(DAA),4-(N,N-di-4-anisylamino)benzo(DAB),and N3,N6(or N2,N7)-bis(di-4-anisylamino)-9 H-carbazole(3,6-DAC or 2,7-DAC)groups.We also review the core type,end cap position and number,how these affect the overall properties of the SM-HTMs,and the resultant PVSC device performances.Finally,the challenges and perspectives for the future development of SM-HTMs are presented.
基金the National Natural Science Foundation ofChina(No21176180)Research Fund for the Doctoral Program of Higher Education of China(No20100032110021) for the financial support
文摘Two novel organic hole-transporting materials have been synthesized by combination of triphenylamines（TPA） viaπ-conjugated bonds using Wittig reaction.The structures were characterized by NMR,FT-IR and HRMS.The optical,electrochemical and thermal properties of the materials were studied in detail.The results show that these two compounds have blue emission,proper HOMO levels and high thermal stability.Furthermore,a quantum chemical calculation on electron distribution of the two compounds was performed, which suggests the current synthesized materials would be promising candidates for hole-transporting materials.
基金supported by the National Natural Science Foundation of China(Nos.61325026,51503209)the Natural Science Foundation of Fujian Province(No.2015H0050)
文摘Three star-shaped truxene-based small molecules（namely TXH,TXM,TXO） were synthesized,characterized and used as hole-transporting materials（HTMs） for perovskite solar cells（Pv SCs）. The device based on TXO delivered a respectable power conversion efficiency（PCE） of 7.89% and a high open-circuit voltage（Voc） of 0.97 V,which far exceeded the values of the devices based on other two small molecules. The highest PCE for the device based on TXO is mainly contributed from its lowest series resistance（Rs） value and largest short-circuit current（Jsc） value under the same circumstances. All these results indicate that TXO is a promising HTM candidate for Pv SCs.
基金Supported by the National High Technology Research and Development Program of China under Grant No 2013AA032205the National Natural Science Foundation of China under Grant Nos 11474018,51272022 and 61575019+1 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant Nos 20120009130005 and 20130009130001the Technological Development Contract under Grant No HETONG-150188-04E008
文摘We present a systematic analysis of the exciton-recombination zone within all-quantum-dot （QD） multilayer films using sensing QD layers in QD-based light-emitting diodes （QLEDs）, and demonstrate the a11-QD multilayer films with different sequences of layers prepared by inserting a sensing blue QD layer denoted as B at various positions within four red QD multilayers denoted as R. We also use different hole transporting layers （PVK, CBP as well as poly-TPD） to prevent the formation of leakage current and to improve the luminance. The results show that the total EL emission is mostly at the fourth （60%） and fifth （40%） QD monolayers, adjacent to ITO. This presents both decreasing current density and increasing brightness with different hole transporting layers, thus resulting in more efficient performance.
基金the financial support from National High-tech R&D Program(863 Program)(2015AA033402)the Science and Technology Planning Project of Tianjin Province,China(No.14TXGCCX00017)+1 种基金Tianjin science and technology plan projects(13ZCZDGX00900)the National Natural Science Foundation of China(No.11474333)
文摘Two electron-rich,solution-processable phenonaphthazine derivatives,5,12-bis(N-[4,4'-bis-(phenyl)aminophen-4''-yi])-phenonaphthazine(BPZTPA)and 5,12-bis(N-[4,4'-bis(methoxy-phenyl)aminophen-4''-yl])-phenonaphthazine(MeO-BPZTPA)have been designed and employed in the fabrication of perovskite solar cells.BPZTPA and MeO-BPZTPA exhibit excellent thermal stabilities,hole mobilities(similar to 10^(-4)cm^(2)/(V.s))and suitable HOMO levels(-5.34 and-5.29 eV,respectively)relative to the valence band of the CH3NH3PbI3 and Au work function,showing their potential as alternative hole-transporting materials(HTMs).Meanwhile,the corresponding mesoporous TiO_(2)/CH_(3)NH_(3)PbI_(3)/HTM/Au devices are investigated,and the best power conversion efficiency of 10.36%has been achieved for MeO-BPZTPA without using p-type dopant.(C)2016 Science Press and Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.and Science Press.All rights reserved.
基金the financial support from the National Science Foundation of China (No.21373007, 21671148)the Tianjin Natural Science Foundation (18JCYBJC21600, 18JCZDJC97000)+1 种基金111 project (B12015)Training Project of Innovation Team of Colleges and Universities in Tianjin (TD13-5020)。
文摘In this work, a comprehensive study on the deliberate molecular design and modifications of electron donors is carried out to elucidate correlations between the methoxy effects and donor configuration of hole-transporting materials(HTMs). Our initial findings demonstrate the donor-dependent methoxy effects. Photovoltaic performance of the HTM with twisted donor highly depends on the methoxy substituent. In contrast, efficiency’s reliance on methoxy is insignificant for the HTM with planar donor. The HTM(M123) featuring the methoxy–substituted carbazole shows a decent power conversion efficiency of 19.33% due to synergistic effects from both planar structure and methoxy. This work gives a guideline to access HTMs reaching both high-performance and good stability.
基金funding from the Italian Ministry of Economic Development(MISE)in the framework of the Operating Agreement with ENEA for Research on the Electric Systemfrom the Italian Ministry of University and Research(MUR)in the framework of“BEST4U”Project,PON R&I 2014-2020.L.V.,M.S.+2 种基金A.D.C.were supported by the European Union's Horizon 2020 Framework Program for funding Research and Innovation under grant agreement no.764047(ESPResSo)no.691664(UNIQUE,Cofund ERANET Action,MUR GA 775970)no.826013(IMPRESSIVE).C.C.and A.S.acknowledge MIUR Grant—Department of Excellence 2018-2022 and the European Union's Horizon 2020 Framework Program for funding Research and Innovation under grant agreement no.764047(ESPResSo).
文摘During the last decade,perovskite solar technologies underwent an impressive development,with power conversion efficiencies reaching 25.5%for single-junction devices and 29.8%for Silicon-Perovskite tandem configurations.Even though research mainly focused on improving the efficiency of perovskite photovoltaics(PV),stability and scalability remain fundamental aspects of a mature photovoltaics technology.For n-i-p structure perovskite solar cells,using poly-triaryl(amine)(PTAA)as hole transport layer(HTL)allowed to achieve marked improvements in device stability compared with other common hole conductors.For p-i-n structure,poly-triaryl(amine)is also routinely used as dopant-free hole transport layer,but problems in perovskite film growth,and its limited resistance to stress and imperfect batch-to-batch reproducibility,hamper its use for device upscaling.Following previous computational investigations,in this work,we report the synthesis of two small-molecule organic hole transport layers(BPT-1,2),aiming to solve the above-mentioned issues and allow upscale to the module level.By using BPT-1 and methylammonium-free perovskite,max.Power conversion efficiencies of 17.26%and 15.42%on a small area(0.09 cm^(2))and mini-module size(2.25 cm^(2)),respectively,were obtained,with a better reproducibility than with poly-triaryl(amine).Moreover,BPT-1 was demonstrated to yield more stable devices compared with poly-triaryl(amine)under ISOS-D1,T1,and L1 accelerated life-test protocols,reaching maximum T_(90)values>1000 h on all tests.
基金supported by the Ministry of Science and Technology of China(2023YFE0210400)the National Natural Science Foundation of China(22361132530,52303237)+1 种基金the Natural Science Foundation of Tianjin(24JCYBJC01540)the Fundamental Research Funds for the Central Universities(023-63253172)。
文摘Carbazole-based self-assembled molecules have been widely adopted as hole-transporting layers(HTLs)in high-performance organic solar cells(OSCs).However,their practical implementation has been constrained by their limited concentration in solutions and poor solvent tolerance.Herein,to address these limitations,we designed two novel trimeric molecules(TPACz-1 and TPACz-2)that synergistically integrate the structural merits of small molecules with the processing advantages of polymers.Notably,TPACz-2 showed exceptional hole-transporting capacity with uniform coverage on indium tin oxide(ITO)substrates,coupled with robust processability characterized by an extended concentration tolerance range(0.2–1.0 mg mL^(-1))and compatibility with a broad range of solvents.Binary OSCs based on TPACz-2 showed an excellent power conversion efficiency(PCE)of 19.65%with a short-circuit current density of 27.49 mA cm^(-2)and a fill factor of 80.9%.At the same time,the corresponding ternary devices exhibited a high PCE exceeding 20%.Furthermore,the TPACz-based devices demonstrated superior ambient stability,retaining~80%of their initial PCE after 680 h at 25%relative humidity,substantially outperforming conventional PEDOT:PSS-based counterparts.This work offers valuable guidance and highlights the crucial role of oligomeric molecular design as a pivotal strategy for the development of innovative HTLs in OSCs.
文摘A series of conductive polymers, i.e., poly（3-methylthiophene） （PMT）, poly（thiophene） （PT）, poly（3-bromothiophene） （PBT） and poly（3-chlorothiophene） （PCT）, were prepared via the electrochemical polymerization process. Subse- quently, their application as hole-transporting materials （HTMs） in CHBNI-I3Pb｜3 perovskite solar cells was explored. It was found that rationally increasing the work function of HTMs proves beneficial in improving the open circuit voltage （Voc） of the devices with an ITO/conductive-polymer/CHBNHBPbIg/C60/BCP/Ag structure. In addition, the higher-Voc devices with a higher-work-function HTM exhibited higher recombination resistances. The highest open circuit voltage of 1.04 V was obtained from devices with PCT, with a work function of -5.4 eV, as the hole-transporting layer. Its power conversion efficiency attained a value of approximately 16.5%, with a high fill factor of 0.764, an appreciable open voltage of 1.01 V and a short circuit current density of 21.4 mA.cm-2. This simple, controllable and low-cost manner of preparing HTMs will be beneficial to the production of large-area perovskite solar cells with a hole-transportin~ laver.
基金The authors gratefully acknowledge the financial support from the National Basic Research Program （2011CB933303 and 2013CB921904） and the National Natural Science Foundation of China （NSFC） （21321001, 21371012 and 11134001）.
文摘Ultrathin polythiophene films prepared via electrochemical polymerization is successfully used as the hole-transporting material, substituting conventional HTM-PEDOT：PSS, in planar p-i-n CH3NH3PbI3 perovskite-based solar cells, affording a series of ITO/polythiophene/CH3NHBPbIB/C60/BCP/Ag devices. The ultrathin polythiophene film possesses good transmittance, high conductivity, a smooth surface, high wettability, compatibility with PbI2 DMF solution, and an energy level matching that of the CH3NH3PbI3 perovskite material. A promising power conversion efficiency of about 15.4%, featuring a high fill factor of 0.774, open voltage of 0.99 V, and short-circuit current density of 20.3 mA·cm^-2 is obtained. The overall performance of the devices is superior to that of cells using PEDOT：PSS. The differences of solar cells with different hole-transfer materials in charge recombination, charge transport and transfer, and device stability are further investigated and demonstrate that polythiophene is a more effective and promising hole-transporting material. This work provides a simple, prompt, controllable, and economic approach for the preparation of an effective hole-transporting material, which undoubtedly offers an alternative method in the future industrial production of perovskite solar cells.
基金supported by the Project of Strategic Importance provided by The Hong Kong Polytechnic University(1-ZE29)the Natural Science Foundation of Hubei Province(2014CFB275)+2 种基金the Special(2016T90724,2014T70735)and General(2015M572187,2013M531737)Postdoctoral Science Foundation of Chinathe National High Technology Research and Development Program(2015AA050601)the National Natural Science Foundation of China(61376013,91433203,11674252)
文摘Organic polymer solar cells （OSCs） and organic-inorganic hybrid perovskite solar cells （PSCs） have achieved notable progress over the past several years. A central topic in these fields is exploring electronically efficient, stable and effective hole-transporting layer （HTL） materials. The goal is to enhance hole-collection ability, reduce charge recombination, increase built-in voltage, and hence improve the performance as well as the device stability. Transition metal oxides （TMOs） semiconductors such as NiOx, CuOx, CrOx, MoOx, WO3, and V2O5, have been widely used as HTLs in OSCs. These TMOs are naturally adopted into PSC as HTLs and shows their importance. There are similarities, and also differences in applying TMOs in these two types of main solution processed solar cells. This concise review is on the recent developments of transition metal oxide HTL in OSCs and PSCs. The paper starts from the discussion of the cation valence and electronic structure of the transition metal oxide materials, followed by analyzing the structure-property relationships of these HTLs, which we attempt to give a systematic introduction about the influences of their cation valence, electronic structure, work ftmction and film property on device performance.
基金supported by the National Natural Science Foundation of China(21606039,21120102036,91233201)the National Basic Research Program of China(2014CB239402)+2 种基金the Swedish Energy Agencythe KnutAlice Wallenberg Foundatioa
文摘The development of alternative low-cost and high-performing hole-transporting materials(HTMs) is of great significance for the potential large-scale application of perovskite solar cells(PSCs) in the future.Here,a facilely synthesized solution-processable copper tetra-(2,4-dimethyl-3-pentoxy) phthalocyanine(CuPc-DMP) via only two simple steps,has been incorporated as a hole-transporting material(HTM) in mesoscopic perovskite solar cells(PSCs).The optimized devices based on such a HTM afford a very competitive power conversion efficiency(PCE) of up to 17.1%measured at 100 mW cm^(-2) AM 1.5G irradiation,which is on par with that of the well-known 2,2',7,7'-tetrakis(N'N'-di-p-methoxyphenylamine)-9,9'-spirobifluorene(spiro-OMeTAD)(16.7%) under equivalent conditions.This is,to the best of our knowledge,the highest value reported so far for metal organic complex-based HTMs in PSCs.The advantages of this HTM observed,such as facile synthetic procedure,superior hole transport characteristic,high photovoltaic performance together with the feasibility of tailoring the molecular structure would make solution-processable copper phthalocyanines as a class of promising HTM that can be further explored in PSCs.The present finding highlights the potential application of solution processed metal organic complexes as HTMs for cost-effective and high-performing PSCs.
基金the National Natural Science Foundation of China(Nos.91833303,51911530155,91733302,22001187,and 52062019)the Key Research and Development Program of Zhejiang Province(No.2020C01001)the Natural Science Research Foundation of Jiangsu Higher Education Institutions(No.20KJB150032).
文摘Quantum-dot light-emitting diodes(QLEDs)are multilayer electroluminescent devices promising for next-generation display and solid-state-lighting technologies.In the state-of-the-art QLEDs,hole-injection layers(HILs)with high work functions are generally used to achieve efficient hole injection.In these devices,Fermi-level pinning,a phenomenon often observed in heterojunctions involving organic semiconductors,can take place in the hole-injection/hole-transporting interfaces.However,an in-depth understanding of the impacts of Fermi-level pinning at the hole-injection/hole-transporting interfaces on the operation and performance of QLEDs is still lacking.Here,we develop a set of NiOx HILs with controlled work functions of 5.2–5.9 eV to investigate QLEDs with Fermi-level pinning at the hole-injection/hole-transporting interfaces.The results show that despite that Fermi-level pinning induces identical apparent hole-injection barriers,the red QLEDs using HILs with higher work functions show improved efficiency roll-off and better operational stability.Remarkably,the devices using the NiOx HILs with a work function of 5.9 eV demonstrate a peak external quantum efficiency of~18.0%and a long T95 operational lifetime of 8,800 h at 1,000 cd·m^(−2),representing the best-performing QLEDs with inorganic HILs.Our work provides a key design principle for future developments of the hole-injection/hole-transporting interfaces of QLEDs.
基金supported by the National Natural Science Foundation of China (21606039, 51661135021, 91233201)the Fundamental Research Funds for the Central UniversitiesSwedish Foundation for Strategic Research (SSF),the Swedish Energy Agency, and the Knut and Alice Wallenberg Foundation
文摘The development of an efficient, stable, and low-cost hole-transporting material (HTM) is of great significance for perovskite solar cells (PSCs) from future commercialization point of view. Herein, we specifically synthesize a dicationic salt of X60 termed X60(TFSI)2, and adopt it as an effective and stable "doping" agent to replace the previously used lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) for the low-cost organic HTM X60 in PSCs. The incorporation of this dicationic salt significantly increases the hole conductivity of X60 by two orders of magnitude from 10-6 to 10-4 S cm-1. The dramatic enhancement of the conductivity leads to an impressive power conversion efficiency (PCE) of 19.0% measured at 1 sun illumination (100 mW cm-2, AM 1.5 G), which is comparable to that of the device doped with LiTFSI (19.3%) under an identical condition. More strikingly, by replacing LiTFSI, the PSC devices incorporating X60(TFSI)2 also show an excellent long-term durability under ambient atmosphere for 30 days, mainly due to the hydrophobic nature of the X60(TFSI)2 doped HTM layer,which can effectively prevent the moisture destroying the perovskite layer. The present work paves the way for the development of highly efficient, stable, and low-cost HTM for potential commercialization of PSCs.
