The vast majority of high-performance perovskite solar cells(PSCs) are based on a formamidinium lead iodide(FAPbI_(3))-dominant composition. Nevertheless, the FA-based perovskite films suffer from undesirable phase tr...The vast majority of high-performance perovskite solar cells(PSCs) are based on a formamidinium lead iodide(FAPbI_(3))-dominant composition. Nevertheless, the FA-based perovskite films suffer from undesirable phase transition and defects-induced non-ideal interfacial recombination, which significantly induces energy loss and hinders the improvement of device performance. Herein, we employed 4-fluorophenylmethylammonium iodide(F-PMAI) to modulate surface structure and energy level alignment of the FA-based perovskite films. The superior optoelectronic films were obtained with reduced trap density, pure α-phase FAPbI_(3) and favorable energy band bending. The lifetime of photogenerated charge carriers increased from 489.3 ns to 1010.6 ns, and a more “p-type” perovskite film was obtained by the post-treatment with F-PMAI. Following this strategy, we demonstrated an improved power conversion efficiency of 22.59% for the FA-based PSCs with an open-circuit voltage loss of 399 m V.展开更多
Realizing simultaneous adjustment of energy levels and work functions in two-dimensional/three-dimensional(2D/3D)perovskite solar cells(PSCs)is a challenge.Here,a pseudohalide 3,5-bis(trifluoromethyl)benzylammonium te...Realizing simultaneous adjustment of energy levels and work functions in two-dimensional/three-dimensional(2D/3D)perovskite solar cells(PSCs)is a challenge.Here,a pseudohalide 3,5-bis(trifluoromethyl)benzylammonium tetrafluoroborate(TFPMABF_(4))was used to react with unreacted Pb I2on the surface of 3D bulky perovskite to form a mixed halide of 2D perovskite denoted(TF-PMA)_(2)FA_(2)Pb_(3)I_(8)(BF_(4))_(2).This novel 2D/3D perovskite enables the simultaneous adjustment of energy levels and work functions on the surface of active layers.Due to the significantly enhanced quality of 2D/3D perovskite film,decreased surface defects and increased charge carrier lifetime,the 2D/3D PSCs exhibit an outstanding power conversion efficiency(PCE)of 25.15%and a high V_(OC)of 1.194 V.Importantly,2D/3D PSCs exhibit remarkable enhancements in environmental stability,unencapsulated devices retaining more than 90%of their initial PCE at 50%humidity for 2,280 h.展开更多
Through strategies such as process optimization,solvent selection,and component tuning,the crystallization of perovskite materials has been effectively controlled,enabling perovskite solar cells(PSCs)to achieve over 2...Through strategies such as process optimization,solvent selection,and component tuning,the crystallization of perovskite materials has been effectively controlled,enabling perovskite solar cells(PSCs)to achieve over 25%power conversion efficiency(PCE).However,as PCE continues to improve,interfacial issues within the devices have emerged as critical bottlenecks,hindering further performance enhancements.Recently,interfacial engineering has driven transformative progress,pushing PCEs to nearly 27%.Building upon these developments,this review first summarizes the pivotal role of interfacial modifications in elevating device performance and then,as a starting point,provides a comprehensive overview of recent advancements in normal,inverted,and tandem structure devices.Finally,based on the current progress of PSCs,preliminary perspectives on future directions are presented.展开更多
Self-assembled monolayers(SAMs),owing to their amphiphilic nature,tend to aggregate,which impedes the formation of a dense and uniform SAM on the substrate.Additionally,the weak adsorption ability of SAMs on the indiu...Self-assembled monolayers(SAMs),owing to their amphiphilic nature,tend to aggregate,which impedes the formation of a dense and uniform SAM on the substrate.Additionally,the weak adsorption ability of SAMs on the indium tin oxide(ITO)surface and the desorption of hydroxyl(OH)from the ITO surface induced by polar solvents can lead to the formation of vacancies.Herein,a dimethylacridine-based SAM is incorporated into the perovskite precursor solution.This SAM can be extruded from the precursor solution and enriched on the bottom surface of the perovskite,filling the vacancies and in situ forming a mixed SAM with MeO-2PACz as a hole-selective layer(HSL).The in situ formed mixed SAM optimizes the energy level alignment between the HSL and the perovskite,facilitating hole extraction and alleviating the residual strain of the perovskite film.Consequently,the perovskite solar cells(PSCs),based on the mixed SAM,achieve a power conversion efficiency(PCE)of 25.69%and exhibit excellent operational stability.When this approach is applied to 1.78 eV bandgap PSC devices,it yields a PCE of 20.08%.This work presents a unique strategy for fabricating both high-quality perovskite films and superior buried interfaces,which is also applicable to wide-bandgap PSCs.展开更多
Inverted perovskite solar cells(PSCs)have stood out in recent years for their great potential in offering low-temperature compatibility,long-term stability and tandem cell suitability.However,challenges persist,partic...Inverted perovskite solar cells(PSCs)have stood out in recent years for their great potential in offering low-temperature compatibility,long-term stability and tandem cell suitability.However,challenges persist,particularly concerning the use of nickel oxide nanoparticles(NiO_(x)NPs)as the hole transport material,where issues such as low conductivity,impurity-induced aggregation and interface redox reactions significantly hinder device performance.In response,this study presents a novel synthesis method for NiO_(x)NPs,leveraging the introduction of ammonium salt dopants(NH_(4)Cl and NH_(4)SCN),and the solar cell utilizing the doped NiO_(x)substrate exhibits much enhanced device performance.Furthermore,doped solar cells reach 23.27%power conversion efficiency(PCE)when a self-assembled monolayer(SAM)is further employed.This study provides critical insights into the synthesis and growth pathways of NiO_(x)NPs,propelling the development of efficient hole transport materials for high-performance PSCs.展开更多
Carbon-based perovskite solar cells(C-PSCs)exhibit notable stability and durability.However,the power conversion efficiency(PCE)is significantly hindered by energy level mismatches,which result in interfacial charge t...Carbon-based perovskite solar cells(C-PSCs)exhibit notable stability and durability.However,the power conversion efficiency(PCE)is significantly hindered by energy level mismatches,which result in interfacial charge transport barriers at the electrode-related interfaces.Herein,we report a back electrode that utilizes atomically dispersed metallic cobalt(Co)in carbon nanosheets(Co_1/CN)to adjust the interfacial energy levels.The electrons in the d-orbitals of Co atoms disrupt the electronic symmetry of the carbon nanosheets(CN),inducing a redistribution of the electronic density of states that leads to a downward shift in the Fermi level and a significantly reduced interfacial energy barrier.As a result,the C-PSCs using Co1/CN as back electrodes achieve a notable PCE of 22.61%with exceptional long-term stability,maintaining 94.4%of their initial efficiency after 1000 h of continuous illumination without encapsulation.This work provides a promising universal method to regulate the energy level of carbon electrodes for C-PSCs and paves the way for more efficient,stable,and scalable solar technologies toward commercialization.展开更多
Lead(Pb)-free Tin(Sn)-based perovskite solar cells(PSCs)have been favored by the community due to their low toxicity,preferable bandgaps,and great potential to achieve high power conversion efficiencies(PCEs).Interfac...Lead(Pb)-free Tin(Sn)-based perovskite solar cells(PSCs)have been favored by the community due to their low toxicity,preferable bandgaps,and great potential to achieve high power conversion efficiencies(PCEs).Interfaces engineering plays important roles in developing highly efficient Sn-based PSCs via passivation of trap defects,alignment of energy levels,and incorporation of low-dimensional Sn-based perovskites.In this review,we summarize the development of Pb-free Sn-based perovskites and their applications in devices,especially the strategies of improving the interfaces.We also provide perspectives for future research.Our aim is to help the development of new and advanced approaches to achieving high-performance environment-friendly Pb-free Sn-based PSCs.展开更多
In recent years, metal halide perovskites have emerged as star semiconducting materials in the field of optoelectronic devices owing to their fascinating optoelectronic properties. Of particular interest are perovskit...In recent years, metal halide perovskites have emerged as star semiconducting materials in the field of optoelectronic devices owing to their fascinating optoelectronic properties. Of particular interest are perovskite solar cells (PSCs), which have witnessed skyrocketing power conversion efficiencies (PCEs) within a short period of time, and were recently certified to reach 25.5%, which is already higher than other thin film photovoltaic technologies[1]. Nevertheless, multiple layers are still needed for state-of-theart PSCs to achieve high PCEs over 21%.展开更多
Two-dimensional(2D) alternating cation(ACI) perovskite surface defects,especially dominant iodine vacancies(V_Ⅰ) and undercoordinated Pb^(2+),limit the performance of perovskite solar cells(PVSCs).To address the issu...Two-dimensional(2D) alternating cation(ACI) perovskite surface defects,especially dominant iodine vacancies(V_Ⅰ) and undercoordinated Pb^(2+),limit the performance of perovskite solar cells(PVSCs).To address the issue,1-butyl-3-methylimidazolium trifluoro-methane-sulfonate(BMIMOTF) and its iodide counterpart(BMIMI) are utilized to modify the perovskite surface respectively.We find that BMIMI can change the perovskite surface,whereas BMIMOTF shows a nondestructive and more effective defect passivation,giving significantly reduced defect density and suppressed charge-carrier nonradiative recombination.This mainly attributes to the marked passivation efficacy of OTF-anion on V_Ⅰ and undercoordinated Pb^(2+),rather than BMIMI^(+) cation.Benefiting from the rational surface-modification of BMMIMOTF,the films exhibit an optimized energy level alignment,enhanced hydrophobicity and suppressed ion migration.Consequently,the BMIMOTF-modified devices achieve an impressive efficiency of 21.38% with a record open-circuit voltage of 1.195 V,which is among the best efficiencies reported for 2D PVSCs,and display greatly enhanced humidity and thermal stability.展开更多
Nickel oxide (NiO_(x)) has significant cost and stability advantages over poly[bis (4-phenyl)(2,4,6-trimethyl phenyl)amine](PTAA) for inverted p-i-n perovskite solar cells (PSCs),but the poor NiO_(x)/perovskite contac...Nickel oxide (NiO_(x)) has significant cost and stability advantages over poly[bis (4-phenyl)(2,4,6-trimethyl phenyl)amine](PTAA) for inverted p-i-n perovskite solar cells (PSCs),but the poor NiO_(x)/perovskite contact stemming from some reactive species at the interface led to suboptimal device performance.To solve this problem,we take a multiple donor molecule approach,using 3,3’-(4,8-bis(hexylthio)benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl)bis(10-(6-bromohexyl)-10H-phenoxazine)(BDT-POZ) as an example,to modify the NiO_(x)/perovskite interface.The primary goal was to reduce the under-coordinated Ni^(≥3+) cations via electron transfer from the donor molecules to NiO_(x),thus mitigating the detrimental reactions between perovskite and NiO_(x).Equally importantly,the hole extraction at the interface was greatly enhanced after the organic donor modification,since the hydrophobic species atop NiO_(x) not only enabled pinhole-free crystallization of the perovskite but also properly tuned the interfacial energy level alignment.Consequently,the PSCs with NiO_(x)/BDT-POZ HTL achieved a high power conversion efficiency (PCE) up to 20.16%,which compared excellently with that of the non-modified devices (17.83%).This work provides a new strategy to tackle the exacting issues that have so far impeded the development of NiO_(x) based PSCs.展开更多
Perovskite film quality is a decisive factor governing the performance and long-term stability of perovskite solar cells(PSCs). To passivate defects for high-quality perovskite films, various additives have been explo...Perovskite film quality is a decisive factor governing the performance and long-term stability of perovskite solar cells(PSCs). To passivate defects for high-quality perovskite films, various additives have been explored in perovskite precursor with notable achievements in the development of highperformance PSCs. Herein, tartaric acid(TA) was applied as additive in perovskite precursor solution to modulate the crystal growth leading to high quality thin films with enhanced multiple preferential orientations favoring efficient charge transport along multiple directions. It is also noticed that TA can improve the energy level alignment in PSCs, which effectively accelerates both carrier extraction and transportation with non-radiative recombination suppressed at the perovskite interfaces. Based on the present perovskite films, the fabricated PSCs achieved an excellent champion power conversion efficiency(PCE) of 21.82% from that of 19.70% for the control device without TA additive. In addition, a PSC with TA additive was shown to exhibit impressive operational stability by retaining 92% of its initial PCE after~1200 h of aging at room temperature in ambient air with a relative humidity of about 10%–25%. In summary, the present work demonstrates a facile and versatile approach by using TA as additive in perovskite precursor to fabricate high quality perovskite films with enhanced multiple preferential orientations for high-efficiency stable PSCs.展开更多
MAPbI_(3) perovskite solar cells(PSCs)exhibit a theoretical open-circuit voltage(V_(OC))of approximately 1.3 V,and minimizing V_(OC) loss is crucial for enhancing their performance.Herein,we focus on MAPbI_(3) PSCs to...MAPbI_(3) perovskite solar cells(PSCs)exhibit a theoretical open-circuit voltage(V_(OC))of approximately 1.3 V,and minimizing V_(OC) loss is crucial for enhancing their performance.Herein,we focus on MAPbI_(3) PSCs to inhibit the interfacial charge recombination and voltage loss through synergistic energy-level grading and lattice matching.The synthesized SrTiO_(3) nanocubes were incorporated into the TiO_(2) electron transport layer to effectively achieve optimal energy alignment with the conduction band of MAPbI_(3),to reduce charge carrier energy loss,and improve carrier extraction.Furthermore,the small lattice mismatch between the perovskite structures of SrTiO_(3) and MAPbI_(3) promoted the growth of high-quality perovskite films with reduced defect density.As a result,the V_(OC) of the MAPbI_(3) PSCs was increased to 1.17 V,and the power conversion efficiency reached 22.19%.This work provides an effective approach to interface optimization to emphasize the energy-level grading and lattice matching in minimizing V_(OC) loss and improving the performance of MAPbI_(3) PSCs.展开更多
Inverted(p-i-n)perovskite solar cells(PSCs)are favored by researchers owing to their superior compatibility with flexible substrates and tandem device fabrication.Additionally,the hole transport layer(HTL)serves as a ...Inverted(p-i-n)perovskite solar cells(PSCs)are favored by researchers owing to their superior compatibility with flexible substrates and tandem device fabrication.Additionally,the hole transport layer(HTL)serves as a template for perovskite growth,which is critical for enhancing the device performance.However,the current research on how the HTL promotes perovskite crystallization is insufficient.Here,4PADCB,a self-assembled monolayer(SAM)hole transport material,was optimized as a superior template for perovskite growth through comparative analysis;accordingly,compact perovskite film with vertical growth was prepared.The better matched energy level alignment between 4PADCB and perovskite suppressed nonradiative recombination at the interface and enabled rapid hole extraction.Moreover,high-quality perovskite film growth on 4PADCB exhibited lower Young's modulus and less residual stress.By integrating 4PADCB into p-i-n PSCs,the optimal device achieved a power conversion efficiency of 24.80%,with an open-circuit voltage of 1.156 V,thus achieving the best rank among devices without perovskite post-treatment,additives,dopants,or intermediate layers.Furthermore,the unencapsulated device demonstrated exceptional thermostability and photostability under maximum power point tracking.Thus,this work provides a new understanding for the development of novel SAMs and perovskite growth,and it is expected to further improve device performance.展开更多
Recently,the chemiluminescence(CL)induced by carbon nanodots(CDs)has intrigued researchers’extensive interests in various applications due to its special light emission principle.However,the difficulty of synthesizin...Recently,the chemiluminescence(CL)induced by carbon nanodots(CDs)has intrigued researchers’extensive interests in various applications due to its special light emission principle.However,the difficulty of synthesizing chemiluminescent CDs with full-spectrum emission severely hinders the further regulation of the CL emission mechanism.Herein,the multi-color-emissive chemiluminescent CDs are rational designed and further synthesized by regulating the sp2-hybrid core and sp3-hybrid surface from the citrate-ammonia molecular in a single solvothermal reaction.More experimental characterizations and density functional theory calculations reveal that the higher temperature can promote the crosslinking polymerization/carbonization of carbon core and the higher protonation of solvent can determine the core size of final CDs,resulting in the variant CL emission from molecular-,crosslinking-and core-states.Thus,the CL emission of the CDs can be further synthesized by tuning the luminescence chromophores in the formation process via regulating the temperature and solvent,enabling the applications of the CL CDs in illumination and information encryption.This study paves a new technology to understand the luminescence of CDs and affords an industry translational potential over traditional chemiluminescent molecular.展开更多
Wide-bandgap mixed-halide perovskite solar cells(WBG-PSCs)are promising top cells for efficient tandem photovoltaics to achieve high power conversion efficiency(PCE)at low cost.However,the open-circuit voltage(V_(OC))...Wide-bandgap mixed-halide perovskite solar cells(WBG-PSCs)are promising top cells for efficient tandem photovoltaics to achieve high power conversion efficiency(PCE)at low cost.However,the open-circuit voltage(V_(OC))of WBG-PSCs is still unsatisfactory as the V_(OC)-deficit is generally larger than 0.45 V.Herein,we report a buried interface engineering strategy that substantially improves the V_(OC)of WBG-PSCs by inserting amphiphilic molecular hole-selective materials featuring with a cyanovinyl phosphonic acid(CPA)anchoring group between the perovskite and substrate.The assembly and redistribution of CPA-based amphiphilic molecules at the perovskite-substrate buried interface not only promotes the growth of a low-defect crystalline perovskite thin film,but also suppresses the photo-induced halide phase separation.The energy level alignment between wide-bandgap perovskite and the hole-selective layer is further improved by modulating the substituents on the triphenylamine donor moiety(methoxyls for MPA-CPA,methyls for Me PA-CPA,and bare TPA-CPA).Using a 1.68 e V bandgap perovskite,the Me PA-CPA-based devices achieved an unprecedentedly high V_(OC)of 1.29 V and PCE of 22.3%under standard AM 1.5 sunlight.The V_(OC)-deficit(<0.40 V)is the lowest value reported for WBG-PSCs.This work not only provides an effective approach to decreasing the V_(OC)-deficit of WBG-PSCs,but also confirms the importance of energy level alignment at the charge-selective layers in PSCs.展开更多
The chemical structure of covalent organic frameworks(COFs)plays a key role in their response to the surface doping strategy used for tuning their electronic character,but it is still not fully understood.To explore a...The chemical structure of covalent organic frameworks(COFs)plays a key role in their response to the surface doping strategy used for tuning their electronic character,but it is still not fully understood.To explore a rational design proposal for their chemical structure,the electronic properties of three n-doped typical COFs,including boroncontaining(COF-1),triazine-based(CTF),and C–C bondlinked(GCOF)COFs,were investigated theoretically in this work.As expected,the chemical doping effects are different for these COFs.The dispersion of the frontier bands,the nuclear-independent chemical shift(NICS)aromaticity index results,distribution of the electron localization function(ELF),and Hirshfeld charge population plots show that part of the transferred electron from dopants will be offset by the intralayer charge transfer of COFs.Thus,chemical doping effects are more significant if the electron distribution in the COFs is more localized.This means the response of COFs to the surface doping strategy should be dominated by the conjugation degree of their chemical structure.Our results prove that the intrinsic conjugation degree of COFs plays a key role in such doping functionalization strategies,which are expected to provide more useful information for the initial structure design of COF materials and facilitate their practical applications as active electronic transport materials in nanoscale devices.展开更多
The reliable information about interface energetics of organic materials, especially the energy level alignment at organic heterostructures is of pronounced importance for unraveling the photon harvesting and charge s...The reliable information about interface energetics of organic materials, especially the energy level alignment at organic heterostructures is of pronounced importance for unraveling the photon harvesting and charge separation process in organic photovoltaic(OPV) cells. This article provides an overview of interface energetics at typical planar and mixed donor-acceptor heterostructures, perovskite/organic hybrid interfaces, and their contact interfaces with charge collection layers. The substrate effect on energy level offsets at organic heterostructures and the processes that control and limit the OPV operation are presented. Recent efforts on interface engineering with electrical doping are also discussed.展开更多
Conjugated polymers have been explored as promising hole-transporting layer(HTL)in lead sulfide(PbS)quantum dot(QD)solar cells.The fine regulation of the inorganic/organic interface is pivotal to realize high device p...Conjugated polymers have been explored as promising hole-transporting layer(HTL)in lead sulfide(PbS)quantum dot(QD)solar cells.The fine regulation of the inorganic/organic interface is pivotal to realize high device performance.In this work,we propose using CsPbI_(3) QDs as the interfacial layer between PbS QD active layer and organic polymer HTL.The relative soft perovskite can mediate the interface and form favorable energy level alignment,improving charge extraction and reducing interfacial charge recombination.As a result,the photovoltaic performance can be efficiently improved from 10.50%to 12.32%.This work may provide new guidelines to the device structural design of QD optoelectronics by integrating different solutionprocessed semiconductors.展开更多
基金funded by the National Natural Science Foundation of China(62004165)the China Postdoctoral Science Foundation(2020M670036)+2 种基金the Natural Science Foundation of Shaanxi Province,China(2020JQ195)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z-007,2020GXLH-Z-025)the Fundamental Research Funds for the Central Universities。
文摘The vast majority of high-performance perovskite solar cells(PSCs) are based on a formamidinium lead iodide(FAPbI_(3))-dominant composition. Nevertheless, the FA-based perovskite films suffer from undesirable phase transition and defects-induced non-ideal interfacial recombination, which significantly induces energy loss and hinders the improvement of device performance. Herein, we employed 4-fluorophenylmethylammonium iodide(F-PMAI) to modulate surface structure and energy level alignment of the FA-based perovskite films. The superior optoelectronic films were obtained with reduced trap density, pure α-phase FAPbI_(3) and favorable energy band bending. The lifetime of photogenerated charge carriers increased from 489.3 ns to 1010.6 ns, and a more “p-type” perovskite film was obtained by the post-treatment with F-PMAI. Following this strategy, we demonstrated an improved power conversion efficiency of 22.59% for the FA-based PSCs with an open-circuit voltage loss of 399 m V.
基金supported by the National Natural Science Foundation of China(21875122)。
文摘Realizing simultaneous adjustment of energy levels and work functions in two-dimensional/three-dimensional(2D/3D)perovskite solar cells(PSCs)is a challenge.Here,a pseudohalide 3,5-bis(trifluoromethyl)benzylammonium tetrafluoroborate(TFPMABF_(4))was used to react with unreacted Pb I2on the surface of 3D bulky perovskite to form a mixed halide of 2D perovskite denoted(TF-PMA)_(2)FA_(2)Pb_(3)I_(8)(BF_(4))_(2).This novel 2D/3D perovskite enables the simultaneous adjustment of energy levels and work functions on the surface of active layers.Due to the significantly enhanced quality of 2D/3D perovskite film,decreased surface defects and increased charge carrier lifetime,the 2D/3D PSCs exhibit an outstanding power conversion efficiency(PCE)of 25.15%and a high V_(OC)of 1.194 V.Importantly,2D/3D PSCs exhibit remarkable enhancements in environmental stability,unencapsulated devices retaining more than 90%of their initial PCE at 50%humidity for 2,280 h.
基金supported by National Natural Science Foundation of China(52302229,62404072)the Key Lab of Modern Optical Technologies of Education Ministry of China,Soochow University(KJS2425)+1 种基金Doctoral Foundation of Henan Polytech-nic University(B2024-72)Science and Technology Research Project of Jiangxi Provincial Department of Education(Grant No.GJJ2400702).
文摘Through strategies such as process optimization,solvent selection,and component tuning,the crystallization of perovskite materials has been effectively controlled,enabling perovskite solar cells(PSCs)to achieve over 25%power conversion efficiency(PCE).However,as PCE continues to improve,interfacial issues within the devices have emerged as critical bottlenecks,hindering further performance enhancements.Recently,interfacial engineering has driven transformative progress,pushing PCEs to nearly 27%.Building upon these developments,this review first summarizes the pivotal role of interfacial modifications in elevating device performance and then,as a starting point,provides a comprehensive overview of recent advancements in normal,inverted,and tandem structure devices.Finally,based on the current progress of PSCs,preliminary perspectives on future directions are presented.
基金supported by the Young Cross Team Project of CAS(No.JCTD-2021-14)the National Natural Science Foundation of China(51925206)Gusu Innovation and Entrepreneur Leading Talents(ZXL2022466)。
文摘Self-assembled monolayers(SAMs),owing to their amphiphilic nature,tend to aggregate,which impedes the formation of a dense and uniform SAM on the substrate.Additionally,the weak adsorption ability of SAMs on the indium tin oxide(ITO)surface and the desorption of hydroxyl(OH)from the ITO surface induced by polar solvents can lead to the formation of vacancies.Herein,a dimethylacridine-based SAM is incorporated into the perovskite precursor solution.This SAM can be extruded from the precursor solution and enriched on the bottom surface of the perovskite,filling the vacancies and in situ forming a mixed SAM with MeO-2PACz as a hole-selective layer(HSL).The in situ formed mixed SAM optimizes the energy level alignment between the HSL and the perovskite,facilitating hole extraction and alleviating the residual strain of the perovskite film.Consequently,the perovskite solar cells(PSCs),based on the mixed SAM,achieve a power conversion efficiency(PCE)of 25.69%and exhibit excellent operational stability.When this approach is applied to 1.78 eV bandgap PSC devices,it yields a PCE of 20.08%.This work presents a unique strategy for fabricating both high-quality perovskite films and superior buried interfaces,which is also applicable to wide-bandgap PSCs.
基金supported by the Open Research Fund of Songshan Lake Materials Laboratory(No.2021SLABFK09)the National Natural Science Foundation of China(No.22109093)+1 种基金the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning and the Shanghai Rising-Star Program(No.19QA1403800)the Project of Innovative Development Agency of Republic of Uzbekistan(No.FZ-20200929177)and Shanghai Technical Service Computing Center of Science and Engineering,Shanghai University.
文摘Inverted perovskite solar cells(PSCs)have stood out in recent years for their great potential in offering low-temperature compatibility,long-term stability and tandem cell suitability.However,challenges persist,particularly concerning the use of nickel oxide nanoparticles(NiO_(x)NPs)as the hole transport material,where issues such as low conductivity,impurity-induced aggregation and interface redox reactions significantly hinder device performance.In response,this study presents a novel synthesis method for NiO_(x)NPs,leveraging the introduction of ammonium salt dopants(NH_(4)Cl and NH_(4)SCN),and the solar cell utilizing the doped NiO_(x)substrate exhibits much enhanced device performance.Furthermore,doped solar cells reach 23.27%power conversion efficiency(PCE)when a self-assembled monolayer(SAM)is further employed.This study provides critical insights into the synthesis and growth pathways of NiO_(x)NPs,propelling the development of efficient hole transport materials for high-performance PSCs.
基金supported by the National Natural Science Foundation of China(22109019,52272193)Fundamental Research Funds for the Central Universities(DUT22LAB602,DUT23RC(3)002)。
文摘Carbon-based perovskite solar cells(C-PSCs)exhibit notable stability and durability.However,the power conversion efficiency(PCE)is significantly hindered by energy level mismatches,which result in interfacial charge transport barriers at the electrode-related interfaces.Herein,we report a back electrode that utilizes atomically dispersed metallic cobalt(Co)in carbon nanosheets(Co_1/CN)to adjust the interfacial energy levels.The electrons in the d-orbitals of Co atoms disrupt the electronic symmetry of the carbon nanosheets(CN),inducing a redistribution of the electronic density of states that leads to a downward shift in the Fermi level and a significantly reduced interfacial energy barrier.As a result,the C-PSCs using Co1/CN as back electrodes achieve a notable PCE of 22.61%with exceptional long-term stability,maintaining 94.4%of their initial efficiency after 1000 h of continuous illumination without encapsulation.This work provides a promising universal method to regulate the energy level of carbon electrodes for C-PSCs and paves the way for more efficient,stable,and scalable solar technologies toward commercialization.
基金supported by the Science and Technology Program of Sichuan Province(Nos.2017GZ0052,2020YFH0079,and 2020JDJQ0030)National Energy Novel Materials Center Project(No.NENMC-I-1701)+1 种基金the Fundamental Research Funds for the Central Universities(Nos.YJ201722,YJ201955)support by National Natural Science Foundation of China(Grant No.U1804132)。
文摘Lead(Pb)-free Tin(Sn)-based perovskite solar cells(PSCs)have been favored by the community due to their low toxicity,preferable bandgaps,and great potential to achieve high power conversion efficiencies(PCEs).Interfaces engineering plays important roles in developing highly efficient Sn-based PSCs via passivation of trap defects,alignment of energy levels,and incorporation of low-dimensional Sn-based perovskites.In this review,we summarize the development of Pb-free Sn-based perovskites and their applications in devices,especially the strategies of improving the interfaces.We also provide perspectives for future research.Our aim is to help the development of new and advanced approaches to achieving high-performance environment-friendly Pb-free Sn-based PSCs.
基金financial support from the Guangdong Basic and Applied Basic Research Foundation(2019A1515110770)financial support from the National Natural Science Foundation of China(No.21965013)。
文摘In recent years, metal halide perovskites have emerged as star semiconducting materials in the field of optoelectronic devices owing to their fascinating optoelectronic properties. Of particular interest are perovskite solar cells (PSCs), which have witnessed skyrocketing power conversion efficiencies (PCEs) within a short period of time, and were recently certified to reach 25.5%, which is already higher than other thin film photovoltaic technologies[1]. Nevertheless, multiple layers are still needed for state-of-theart PSCs to achieve high PCEs over 21%.
基金financially supported by the National Natural Science Foundation of China (62174021 and 62104028)the Creative Research Groups of the National Natural Science Foundation of Sichuan Province (2023NSFSC1973)+7 种基金the Sichuan Science and Technology Program (MZGC20230008)the Natural Science Foundation of Sichuan Province (2022NSFSC0899)the China Postdoctoral Science Foundation (2021M700689)the Grant SCITLAB (20012) of Intelligent Terminal Key Laboratory of Sichuan ProvinceFundamental Research Funds for the Central Universities (ZYGX2019J054)the Guangdong Basic and Applied Basic Research Foundation (2019A1515110438)sponsored by the University of Kentuckythe Sichuan Province Key Laboratory of Display Science and Technology。
文摘Two-dimensional(2D) alternating cation(ACI) perovskite surface defects,especially dominant iodine vacancies(V_Ⅰ) and undercoordinated Pb^(2+),limit the performance of perovskite solar cells(PVSCs).To address the issue,1-butyl-3-methylimidazolium trifluoro-methane-sulfonate(BMIMOTF) and its iodide counterpart(BMIMI) are utilized to modify the perovskite surface respectively.We find that BMIMI can change the perovskite surface,whereas BMIMOTF shows a nondestructive and more effective defect passivation,giving significantly reduced defect density and suppressed charge-carrier nonradiative recombination.This mainly attributes to the marked passivation efficacy of OTF-anion on V_Ⅰ and undercoordinated Pb^(2+),rather than BMIMI^(+) cation.Benefiting from the rational surface-modification of BMMIMOTF,the films exhibit an optimized energy level alignment,enhanced hydrophobicity and suppressed ion migration.Consequently,the BMIMOTF-modified devices achieve an impressive efficiency of 21.38% with a record open-circuit voltage of 1.195 V,which is among the best efficiencies reported for 2D PVSCs,and display greatly enhanced humidity and thermal stability.
基金the support from NSFC(U2001217,21972006,51803035)the Shenzhen Peacock Plan(KQTD2016053015544057)+4 种基金the Shenzhen-Hong Kong Innovation Circle United Research Project(SGLH20180622092406130)the Nanshan Pilot Plan(LHTD20170001)the Guangdong Basic and Applied Basic Research Foundation(2020A1515110981)the Research Fund Program of Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices(2019B121203003)the Shenzhen Fundamental Research Program(JCYJ20190813105205501)。
文摘Nickel oxide (NiO_(x)) has significant cost and stability advantages over poly[bis (4-phenyl)(2,4,6-trimethyl phenyl)amine](PTAA) for inverted p-i-n perovskite solar cells (PSCs),but the poor NiO_(x)/perovskite contact stemming from some reactive species at the interface led to suboptimal device performance.To solve this problem,we take a multiple donor molecule approach,using 3,3’-(4,8-bis(hexylthio)benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl)bis(10-(6-bromohexyl)-10H-phenoxazine)(BDT-POZ) as an example,to modify the NiO_(x)/perovskite interface.The primary goal was to reduce the under-coordinated Ni^(≥3+) cations via electron transfer from the donor molecules to NiO_(x),thus mitigating the detrimental reactions between perovskite and NiO_(x).Equally importantly,the hole extraction at the interface was greatly enhanced after the organic donor modification,since the hydrophobic species atop NiO_(x) not only enabled pinhole-free crystallization of the perovskite but also properly tuned the interfacial energy level alignment.Consequently,the PSCs with NiO_(x)/BDT-POZ HTL achieved a high power conversion efficiency (PCE) up to 20.16%,which compared excellently with that of the non-modified devices (17.83%).This work provides a new strategy to tackle the exacting issues that have so far impeded the development of NiO_(x) based PSCs.
基金supported by the National Key Research and Development Program of China 2017YFA0403403 and 2017YFB0701901the Natural Science Foundation of China 12075303, 11675252 and U1632265。
文摘Perovskite film quality is a decisive factor governing the performance and long-term stability of perovskite solar cells(PSCs). To passivate defects for high-quality perovskite films, various additives have been explored in perovskite precursor with notable achievements in the development of highperformance PSCs. Herein, tartaric acid(TA) was applied as additive in perovskite precursor solution to modulate the crystal growth leading to high quality thin films with enhanced multiple preferential orientations favoring efficient charge transport along multiple directions. It is also noticed that TA can improve the energy level alignment in PSCs, which effectively accelerates both carrier extraction and transportation with non-radiative recombination suppressed at the perovskite interfaces. Based on the present perovskite films, the fabricated PSCs achieved an excellent champion power conversion efficiency(PCE) of 21.82% from that of 19.70% for the control device without TA additive. In addition, a PSC with TA additive was shown to exhibit impressive operational stability by retaining 92% of its initial PCE after~1200 h of aging at room temperature in ambient air with a relative humidity of about 10%–25%. In summary, the present work demonstrates a facile and versatile approach by using TA as additive in perovskite precursor to fabricate high quality perovskite films with enhanced multiple preferential orientations for high-efficiency stable PSCs.
基金supported by the Ministry of Education of China (IRT1148)the National Natural Science Foundation of China (52102165, 62474056)the Natural Science Foundation of Nanjing University of Posts and Telecommunications (NY221029, NY222165)。
文摘MAPbI_(3) perovskite solar cells(PSCs)exhibit a theoretical open-circuit voltage(V_(OC))of approximately 1.3 V,and minimizing V_(OC) loss is crucial for enhancing their performance.Herein,we focus on MAPbI_(3) PSCs to inhibit the interfacial charge recombination and voltage loss through synergistic energy-level grading and lattice matching.The synthesized SrTiO_(3) nanocubes were incorporated into the TiO_(2) electron transport layer to effectively achieve optimal energy alignment with the conduction band of MAPbI_(3),to reduce charge carrier energy loss,and improve carrier extraction.Furthermore,the small lattice mismatch between the perovskite structures of SrTiO_(3) and MAPbI_(3) promoted the growth of high-quality perovskite films with reduced defect density.As a result,the V_(OC) of the MAPbI_(3) PSCs was increased to 1.17 V,and the power conversion efficiency reached 22.19%.This work provides an effective approach to interface optimization to emphasize the energy-level grading and lattice matching in minimizing V_(OC) loss and improving the performance of MAPbI_(3) PSCs.
基金supported by the National Science Fund for Distinguished Young Scholars(21925506)National Natural Science Foundation of China(U21A20331,81903743,22209192 and 62275251)+1 种基金Natural Science Foundation of Zhejiang Province(LY24F040002)China Postdoctoral Science Foundation(2022M713242).
文摘Inverted(p-i-n)perovskite solar cells(PSCs)are favored by researchers owing to their superior compatibility with flexible substrates and tandem device fabrication.Additionally,the hole transport layer(HTL)serves as a template for perovskite growth,which is critical for enhancing the device performance.However,the current research on how the HTL promotes perovskite crystallization is insufficient.Here,4PADCB,a self-assembled monolayer(SAM)hole transport material,was optimized as a superior template for perovskite growth through comparative analysis;accordingly,compact perovskite film with vertical growth was prepared.The better matched energy level alignment between 4PADCB and perovskite suppressed nonradiative recombination at the interface and enabled rapid hole extraction.Moreover,high-quality perovskite film growth on 4PADCB exhibited lower Young's modulus and less residual stress.By integrating 4PADCB into p-i-n PSCs,the optimal device achieved a power conversion efficiency of 24.80%,with an open-circuit voltage of 1.156 V,thus achieving the best rank among devices without perovskite post-treatment,additives,dopants,or intermediate layers.Furthermore,the unencapsulated device demonstrated exceptional thermostability and photostability under maximum power point tracking.Thus,this work provides a new understanding for the development of novel SAMs and perovskite growth,and it is expected to further improve device performance.
基金the National Natural Science Foundation of China(Nos.U2004168,12074348,11974317,12261141661,and 62204223)the China Postdoctoral Science Foundation(No.2022TQ0307)the Natural Science Foundation of Henan Province(Nos.212300410078 and 222102310664)。
文摘Recently,the chemiluminescence(CL)induced by carbon nanodots(CDs)has intrigued researchers’extensive interests in various applications due to its special light emission principle.However,the difficulty of synthesizing chemiluminescent CDs with full-spectrum emission severely hinders the further regulation of the CL emission mechanism.Herein,the multi-color-emissive chemiluminescent CDs are rational designed and further synthesized by regulating the sp2-hybrid core and sp3-hybrid surface from the citrate-ammonia molecular in a single solvothermal reaction.More experimental characterizations and density functional theory calculations reveal that the higher temperature can promote the crosslinking polymerization/carbonization of carbon core and the higher protonation of solvent can determine the core size of final CDs,resulting in the variant CL emission from molecular-,crosslinking-and core-states.Thus,the CL emission of the CDs can be further synthesized by tuning the luminescence chromophores in the formation process via regulating the temperature and solvent,enabling the applications of the CL CDs in illumination and information encryption.This study paves a new technology to understand the luminescence of CDs and affords an industry translational potential over traditional chemiluminescent molecular.
基金supported by the National Natural Science Foundation of China(22179037)Shanghai pilot program for Basic Research(22TQ1400100-1)+3 种基金Shanghai Municipal Science and Technology Major Project(2018SHZDZX03,21JC1401700)the Programmer of Introducing Talents of Discipline to Universities(B16017)the Fundamental Research Funds for the Central Universitiessupport from Royal Society of Chemistry(R23-0749928359)。
文摘Wide-bandgap mixed-halide perovskite solar cells(WBG-PSCs)are promising top cells for efficient tandem photovoltaics to achieve high power conversion efficiency(PCE)at low cost.However,the open-circuit voltage(V_(OC))of WBG-PSCs is still unsatisfactory as the V_(OC)-deficit is generally larger than 0.45 V.Herein,we report a buried interface engineering strategy that substantially improves the V_(OC)of WBG-PSCs by inserting amphiphilic molecular hole-selective materials featuring with a cyanovinyl phosphonic acid(CPA)anchoring group between the perovskite and substrate.The assembly and redistribution of CPA-based amphiphilic molecules at the perovskite-substrate buried interface not only promotes the growth of a low-defect crystalline perovskite thin film,but also suppresses the photo-induced halide phase separation.The energy level alignment between wide-bandgap perovskite and the hole-selective layer is further improved by modulating the substituents on the triphenylamine donor moiety(methoxyls for MPA-CPA,methyls for Me PA-CPA,and bare TPA-CPA).Using a 1.68 e V bandgap perovskite,the Me PA-CPA-based devices achieved an unprecedentedly high V_(OC)of 1.29 V and PCE of 22.3%under standard AM 1.5 sunlight.The V_(OC)-deficit(<0.40 V)is the lowest value reported for WBG-PSCs.This work not only provides an effective approach to decreasing the V_(OC)-deficit of WBG-PSCs,but also confirms the importance of energy level alignment at the charge-selective layers in PSCs.
基金supported by the Key Program of the National Natural Science Foundation of China(52336003)the National Natural Science Foundation of China(22373054,52176076)+2 种基金the Natural Science Foundation of Shandong Province(ZR2020MB045)the Key R&D Program of Shandong Province(Major Science and Technology Innovation Project)(2023CXGC010315)the Taishan Scholar Project of Shandong Province(China)(ts20190937).
文摘The chemical structure of covalent organic frameworks(COFs)plays a key role in their response to the surface doping strategy used for tuning their electronic character,but it is still not fully understood.To explore a rational design proposal for their chemical structure,the electronic properties of three n-doped typical COFs,including boroncontaining(COF-1),triazine-based(CTF),and C–C bondlinked(GCOF)COFs,were investigated theoretically in this work.As expected,the chemical doping effects are different for these COFs.The dispersion of the frontier bands,the nuclear-independent chemical shift(NICS)aromaticity index results,distribution of the electron localization function(ELF),and Hirshfeld charge population plots show that part of the transferred electron from dopants will be offset by the intralayer charge transfer of COFs.Thus,chemical doping effects are more significant if the electron distribution in the COFs is more localized.This means the response of COFs to the surface doping strategy should be dominated by the conjugation degree of their chemical structure.Our results prove that the intrinsic conjugation degree of COFs plays a key role in such doping functionalization strategies,which are expected to provide more useful information for the initial structure design of COF materials and facilitate their practical applications as active electronic transport materials in nanoscale devices.
基金supported by the National Basic Research Program of China (2014CB932600)the National Natural Science Foundation of China (91433116, 11474214)+2 种基金Jiangsu Science and Technology Department (BK20140053)Bureau of Science and Technology of Suzhou Municipality (SYG201525, ZXG201422)the project of the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions
文摘The reliable information about interface energetics of organic materials, especially the energy level alignment at organic heterostructures is of pronounced importance for unraveling the photon harvesting and charge separation process in organic photovoltaic(OPV) cells. This article provides an overview of interface energetics at typical planar and mixed donor-acceptor heterostructures, perovskite/organic hybrid interfaces, and their contact interfaces with charge collection layers. The substrate effect on energy level offsets at organic heterostructures and the processes that control and limit the OPV operation are presented. Recent efforts on interface engineering with electrical doping are also discussed.
基金supported by the National Natural Science Foundation of China(Nos.92163114,22161142003,52002260,62022081,and 61974099)the Natural Science Foundation of Jiangsu Province of China(No.BK20200872)+3 种基金the State Key Laboratory of applied optics(No.SKLAO2020001A03)Postdoctoral Science Foundation of China(No.2021M702415)This work is also supported by Suzhou Key Laboratory of Functional Nano&Soft Materials,Collaborative Innovation Center of Suzhou Nano Science&Technology,the 111 Project,and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices.K.W.acknowledges the funding support from National Key Research and Development Program(No.2017YFE0120400)National Natural Science Foundation of China(No.61875082).
文摘Conjugated polymers have been explored as promising hole-transporting layer(HTL)in lead sulfide(PbS)quantum dot(QD)solar cells.The fine regulation of the inorganic/organic interface is pivotal to realize high device performance.In this work,we propose using CsPbI_(3) QDs as the interfacial layer between PbS QD active layer and organic polymer HTL.The relative soft perovskite can mediate the interface and form favorable energy level alignment,improving charge extraction and reducing interfacial charge recombination.As a result,the photovoltaic performance can be efficiently improved from 10.50%to 12.32%.This work may provide new guidelines to the device structural design of QD optoelectronics by integrating different solutionprocessed semiconductors.
