We report a transition metal such as manganese doped methylammonium lead halide perovskite(MA(Pb:Mn)I_(3)) solar cell with an power conversion efficiency(PCE) over 20%. The rational design and fabrication of MA(Pb:Mn)...We report a transition metal such as manganese doped methylammonium lead halide perovskite(MA(Pb:Mn)I_(3)) solar cell with an power conversion efficiency(PCE) over 20%. The rational design and fabrication of MA(Pb:Mn)I3 lead to the enhancements of all the photovoltaic parameters. To incorporate Mn can effectively eliminate the trap-assist and bi-molecular recombination. The photo-absorption ability at shorter wavelengths(i.e., less than 500 nm) and charge carrier lifetime can be elaborated. More importantly, the existence of the Mn^(2+)-I~--Mn^(3+)motif contributes for the double exchange effect, giving rise to the charge/spin transport. By a combination of linearly and circularly polarized photo-excitations, we have explicitly determined the role of intrinsic spin–orbit coupling(SOC) in MA(Pb:Mn)I_(3). More dark states are expected to be available for the photocurrent generation. This study may pave the way for deep understandings of transition metals doped hybrid perovskites for highly efficient solar cell applications.展开更多
Lead(Pb)-zinc(Zn)slags contain large amounts of Pb,causing irreversible damage to the environment.Therefore,developing an effective strategy to extract Pb from Pb-Zn slags and convert them into a renewable high-value ...Lead(Pb)-zinc(Zn)slags contain large amounts of Pb,causing irreversible damage to the environment.Therefore,developing an effective strategy to extract Pb from Pb-Zn slags and convert them into a renewable high-value catalyst not only solves the energy crisis but also reduces environmental pollution.Herein,we present a viable strategy to recycle Pb and iron(Fe)from Pb-Zn slags for the fabrication of efficient methylammonium lead tri-iodide(r-MAPbI_(3))piezocatalysts with single-atom Fe-N_(4) sites.Intriguingly,atomically dispersed Fe sites from Pb-Zn slags,which coordinated with N in the neighboring four CH3NH3 to form the FeN_(4) configuration,were detected in the as-obtained r-MAPbI_(3) by synchrotron X-ray absorption spectroscopy.The introduction of Fe single atoms amplified the polarization of MAPbI_(3) and upshifted the d-band center of MAPbI_(3).This not only enhanced the piezoelectric response of MAPbI_(3) but also promoted the proton transfer during the hydrogen evolution process.Due to the decoration of Fe single atoms,r-MAPbI_(3) showed a pronounced H2 yield of 322.4μmol g^(−1) h^(−1),which was 2.52 times that of MAPbI_(3) synthesized using commercially available reagents.This simple yet robust strategy to manufactureMAPbI_(3) piezocatalysts paves a novel way to the large-scale and value-added consumption of Pb-containing waste residues.展开更多
Hybrid organic-inorganic perovskites are currently considered the most promising next-generation photovoltaic material.However,poor stability,arising from structural degradation under exposure to moisture,heat,and str...Hybrid organic-inorganic perovskites are currently considered the most promising next-generation photovoltaic material.However,poor stability,arising from structural degradation under exposure to moisture,heat,and strong current,remains a critical challenge for their device applications.Using ab initio nonadiabatic molecular dynamics,we demonstrate that methylamine fragments deriving from the dissociation of the methylammonium cation can undermine structural stability,produce deep hole traps,and decrease charge carrier lifetimes by 1-3 orders of magnitude.Both stability and charge lifetime can be restored by methylamine passivation with chlorines,which withdraw electrons from the lone electron pair of methylamine and bring the trap levels down into the valence band.The charge lifetime of the passivated system is even longer than that of the pristine perovskite.The simulations reveal the detailed microscopic mechanism underlying deterioration of perovskite performance due to molecular defects,and demonstrate an effective defect passivation strategy to obtain highly efficient and stable perovskite solar cells.展开更多
Solvent residue is inevitable to occur in solution processed thin films,but its influence on the thin film quality has not been identified and addressed to date.Methylammonium acetate(MAAc)ionic liquid has recently be...Solvent residue is inevitable to occur in solution processed thin films,but its influence on the thin film quality has not been identified and addressed to date.Methylammonium acetate(MAAc)ionic liquid has recently been realized as an environmentally friendly solvent for solution processed perovskites.The specific high viscosity,low vapor pressure and strong association with perovskite precursor of the MAAc solvent is a double-edged sword,which endowed an advantageously ambient air operational and anti-solvent free perovskite deposition,but the MAAc is likely to be retained within the film and bring in detrimental effects on device performance of the corresponding solar cells.Herein,we reported a novel route to eliminate the residual solvent via a facial hydrochloric acid(HCl)annealing post-treatment(HAAP).In particular,chemical displacement reaction between the incorporated HCl and residual MAAc can be initiated to form volatile MACl and HAc,efficiently extracting MAAc residue.In the meanwhile,the stimulated mass transport via downward penetration and upward escape can trigger secondary perovskite growth with enlarged grain size and smoothened surface,leading to reduced defect state and improved interfacial contact intimacy,and also partial chloride ions are able to enter the crystal lattice to stabilize perovskite phase structure.As a result,a champion efficiency up to20.78%originating from enhanced Voc was achieved,and more than 96%of its initial efficiency can be maintained after 1000 h shelf-storage.展开更多
Lead halide perovskites of the type APbX3(where A=methylammonium MA,formamidinium FA,or cesium and X=iodide and bromide),in a singlecrystal form or more often as polycrystalline films,have already shown unique optoele...Lead halide perovskites of the type APbX3(where A=methylammonium MA,formamidinium FA,or cesium and X=iodide and bromide),in a singlecrystal form or more often as polycrystalline films,have already shown unique optoelectronic properties,comparable with those of the best singlecrystal semiconductors.To form a properly crystalline iodide or iodide/bromide,perovskite and achieve high performance in solar cells,sources containing only iodide and bromide salts(PbI2,PbBr2,MAI,FAI,CsI,MABr)are typically used as precursor materials.However,recently,most of the record perovskites contain MACl as additive to control their crystallization,revisiting the importance of methylammonium cation excess and chloride incorporation in perovskites,previously highlighted by Snaith’s group back in 2012.Here,we review the background and recent progress in MACl-mediated crystallization of perovskites,as well as the impact of the additive in solar cells.In particular,we describe the current understanding of the mechanism of perovskite crystallization process and defect passivation at grain boundaries in the presence of MACl.We then discuss the spectacular results(in terms of record efficiencies,stability,and up-scaling)that have been delivered by solar cells employing MACl-incorporated perovskites,and give an outlook of future research avenues that might bring perovskite solar cells closer to commercialization.展开更多
A controllable crystallization is of practical importance to produce high-quality perovskite thin films with reduced structural defects.Lewis bases as electron-pair donor chemicals can strongly coordinate to lead ions...A controllable crystallization is of practical importance to produce high-quality perovskite thin films with reduced structural defects.Lewis bases as electron-pair donor chemicals can strongly coordinate to lead ions and have been extensively employed to manipulate the growth of perovskite crystals.In this work,we demonstrate a series of Lewis-base amides,for morphological regulation of methylammonium lead triiodide(MAPbI3)thin films.The screened acetamide was demonstrated to decently improve the grain size,along with a spatial distribution at grain boundaries(GBs).The mesostructured solar cells of acetamide-modified absorbers yielded an optimized power conversion efficiency(PCE)of 20.04%with a mitigated open-circuit voltage(V_(OC))deficit of 0.39 V.This work provides a facile and cost-effective strategy toward controllable fabrication of high-performance MAPbI3 solar cells.展开更多
Aromatic bromides are important chemicals in nature and chemical industries.However,their tra‐ditional synthesis routes suffer from low atomic economy and pollutant formation.Herein,we show that organic-inorganic hyb...Aromatic bromides are important chemicals in nature and chemical industries.However,their tra‐ditional synthesis routes suffer from low atomic economy and pollutant formation.Herein,we show that organic-inorganic hybrid perovskite methylammonium lead bromide(MAPbBr_(3))nanocrystals stabilized in aqueous HBr solution can achieve simultaneous aromatic bromination and hydrogen evolution using HBr as the bromine source under visible light irradiation.By hybridizing MAPbBr_(3) with Pt/Ta_(2)O_(5) and poly(3,4‐ethylenedioxythiophene)polystyrene sulfonate as electron‐and hole‐transporting motifs,aromatic bromides were achieved from aromatic compounds with high yield(up to 99%)and selectivity(up to 99%)with the addition of N,N‐dimethylformamide or its analogs.The mechanistic studies revealed that the bromination proceeds via an electrophilic attack pathway and that HOBr may be the key intermediate in the bromination reaction.展开更多
Defect levels in semiconductor band gaps play a crucial role in functionalized semiconductors for practical applications in optoelectronics;however,first-principle defect calculations based on exchange-correlation fun...Defect levels in semiconductor band gaps play a crucial role in functionalized semiconductors for practical applications in optoelectronics;however,first-principle defect calculations based on exchange-correlation functionals,such as local density approximation,grand gradient approximation(GGA),and hybrid functionals,either underestimate band gaps or misplace defect levels.In this study,we revisited iodine defects in CH_(3)NH_(3)PbI_(3) by combining the accuracy of total energy calculations of GGA and single-electron level calculation of the GW method.The combined approach predicted neutral Im_(i) to be unstable and the transition level of Im_(i)(+1/-1)to be close to the valence band maximum.Therefore,Im_(i) may not be as detrimental as previously reported.Moreover,Vm I may be unstable in the-1 charged state but could still be detrimental owing to the deep transition level of Vm I(+1/0).These results could facilitate the further understanding of the intrinsic point defect and defect passivation observed in CH_(3)NH_(3)PbI_(3).展开更多
Efficiency enhancement of Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) solar cell devices was performed by using iso-butyl ammonium iodide(IBA)passivated on Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) films.The n-i-p structure of pero...Efficiency enhancement of Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) solar cell devices was performed by using iso-butyl ammonium iodide(IBA)passivated on Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) films.The n-i-p structure of perovskite solar cell devices was fabricated with the structure of FTO/SnO_(2)/Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3)(FTO,i.e.,fluorine doped tin oxide)and IBA/Spiro-OMeTAD/Ag.The effect of different weights of IBA passivated on Cs-doped perovskite solar cells(PSCs)was systematically investigated and compared with non-passivated devices.It was found that the 5-mg IBA-passivated devices exhibited a high power conversion efficiency(PCE)of 15.49%higher than 12.64%of non-IBA-passivated devices.The improvement of photovoltaic parameters of the 5-mg IBA-passivated device can be clearly observed compared to the Cs-doped device.The better performance of the IBA-passivated device can be confirmed by the reduction of PbI_(2) phase in the crystal structure,lower charge recombination rate,lower charge transfer resistance,and improved contact angle of perovskite films.Therefore,IBA passivation on Cs_(0.1)(CH_(3)NH)_(0.9)PbI_(3) is a promising technique to improve the efficiency of Cs-doped perovskite solar cells.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 61634001, 11942413, 61974010, and 61904011)the Intergovernmental Cooperation Project, National Key Research and Development Program, Ministry of Science and Technology, China (Grant No. 2019YFE0108400)。
文摘We report a transition metal such as manganese doped methylammonium lead halide perovskite(MA(Pb:Mn)I_(3)) solar cell with an power conversion efficiency(PCE) over 20%. The rational design and fabrication of MA(Pb:Mn)I3 lead to the enhancements of all the photovoltaic parameters. To incorporate Mn can effectively eliminate the trap-assist and bi-molecular recombination. The photo-absorption ability at shorter wavelengths(i.e., less than 500 nm) and charge carrier lifetime can be elaborated. More importantly, the existence of the Mn^(2+)-I~--Mn^(3+)motif contributes for the double exchange effect, giving rise to the charge/spin transport. By a combination of linearly and circularly polarized photo-excitations, we have explicitly determined the role of intrinsic spin–orbit coupling(SOC) in MA(Pb:Mn)I_(3). More dark states are expected to be available for the photocurrent generation. This study may pave the way for deep understandings of transition metals doped hybrid perovskites for highly efficient solar cell applications.
基金supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52121004,U23B20166)Guangdong Basic and Applied Basic Research Foundation(2024A1515030039,2025A1515010312).
文摘Lead(Pb)-zinc(Zn)slags contain large amounts of Pb,causing irreversible damage to the environment.Therefore,developing an effective strategy to extract Pb from Pb-Zn slags and convert them into a renewable high-value catalyst not only solves the energy crisis but also reduces environmental pollution.Herein,we present a viable strategy to recycle Pb and iron(Fe)from Pb-Zn slags for the fabrication of efficient methylammonium lead tri-iodide(r-MAPbI_(3))piezocatalysts with single-atom Fe-N_(4) sites.Intriguingly,atomically dispersed Fe sites from Pb-Zn slags,which coordinated with N in the neighboring four CH3NH3 to form the FeN_(4) configuration,were detected in the as-obtained r-MAPbI_(3) by synchrotron X-ray absorption spectroscopy.The introduction of Fe single atoms amplified the polarization of MAPbI_(3) and upshifted the d-band center of MAPbI_(3).This not only enhanced the piezoelectric response of MAPbI_(3) but also promoted the proton transfer during the hydrogen evolution process.Due to the decoration of Fe single atoms,r-MAPbI_(3) showed a pronounced H2 yield of 322.4μmol g^(−1) h^(−1),which was 2.52 times that of MAPbI_(3) synthesized using commercially available reagents.This simple yet robust strategy to manufactureMAPbI_(3) piezocatalysts paves a novel way to the large-scale and value-added consumption of Pb-containing waste residues.
基金This work was supported by the Beijing Natural Science Foundation(No.2212031)the National Natural Science Foundation of China(Nos.21973006,51861135101,and 21520102005)R.L.acknowledges the financial support by the Recruitment Program of Global Youth Experts of China and the Beijing Normal University Startup.O.V.P.acknowledges the support of the US Department of Energy(No.DE-SC0014429).
文摘Hybrid organic-inorganic perovskites are currently considered the most promising next-generation photovoltaic material.However,poor stability,arising from structural degradation under exposure to moisture,heat,and strong current,remains a critical challenge for their device applications.Using ab initio nonadiabatic molecular dynamics,we demonstrate that methylamine fragments deriving from the dissociation of the methylammonium cation can undermine structural stability,produce deep hole traps,and decrease charge carrier lifetimes by 1-3 orders of magnitude.Both stability and charge lifetime can be restored by methylamine passivation with chlorines,which withdraw electrons from the lone electron pair of methylamine and bring the trap levels down into the valence band.The charge lifetime of the passivated system is even longer than that of the pristine perovskite.The simulations reveal the detailed microscopic mechanism underlying deterioration of perovskite performance due to molecular defects,and demonstrate an effective defect passivation strategy to obtain highly efficient and stable perovskite solar cells.
基金financially supported by the National Natural Science Foundation of China(Grants 51972172,61705102,61605073,61935017 and 91833304)Projects of International Cooperation and Exchanges NSFC(51811530018)+3 种基金the Young 1000 Talents Global Recruitment Program of Chinathe Jiangsu Specially Appointed Professor Program“Six talent peaks”Project in Jiangsu Province,Chinathe fellowship of China Postdoctoral Science Foundation(2020M672181)。
文摘Solvent residue is inevitable to occur in solution processed thin films,but its influence on the thin film quality has not been identified and addressed to date.Methylammonium acetate(MAAc)ionic liquid has recently been realized as an environmentally friendly solvent for solution processed perovskites.The specific high viscosity,low vapor pressure and strong association with perovskite precursor of the MAAc solvent is a double-edged sword,which endowed an advantageously ambient air operational and anti-solvent free perovskite deposition,but the MAAc is likely to be retained within the film and bring in detrimental effects on device performance of the corresponding solar cells.Herein,we reported a novel route to eliminate the residual solvent via a facial hydrochloric acid(HCl)annealing post-treatment(HAAP).In particular,chemical displacement reaction between the incorporated HCl and residual MAAc can be initiated to form volatile MACl and HAc,efficiently extracting MAAc residue.In the meanwhile,the stimulated mass transport via downward penetration and upward escape can trigger secondary perovskite growth with enlarged grain size and smoothened surface,leading to reduced defect state and improved interfacial contact intimacy,and also partial chloride ions are able to enter the crystal lattice to stabilize perovskite phase structure.As a result,a champion efficiency up to20.78%originating from enhanced Voc was achieved,and more than 96%of its initial efficiency can be maintained after 1000 h shelf-storage.
基金supported by the“RESEARCH PROJECTS FOR EXCELLENCE IKY/SIEMENS”the“IKY FELLOWSHIPS OF EXCELLENCE FOR POSTGRADUATE STUDIES IN GREECE-SIEMENS PROGRAMME”Programmes
文摘Lead halide perovskites of the type APbX3(where A=methylammonium MA,formamidinium FA,or cesium and X=iodide and bromide),in a singlecrystal form or more often as polycrystalline films,have already shown unique optoelectronic properties,comparable with those of the best singlecrystal semiconductors.To form a properly crystalline iodide or iodide/bromide,perovskite and achieve high performance in solar cells,sources containing only iodide and bromide salts(PbI2,PbBr2,MAI,FAI,CsI,MABr)are typically used as precursor materials.However,recently,most of the record perovskites contain MACl as additive to control their crystallization,revisiting the importance of methylammonium cation excess and chloride incorporation in perovskites,previously highlighted by Snaith’s group back in 2012.Here,we review the background and recent progress in MACl-mediated crystallization of perovskites,as well as the impact of the additive in solar cells.In particular,we describe the current understanding of the mechanism of perovskite crystallization process and defect passivation at grain boundaries in the presence of MACl.We then discuss the spectacular results(in terms of record efficiencies,stability,and up-scaling)that have been delivered by solar cells employing MACl-incorporated perovskites,and give an outlook of future research avenues that might bring perovskite solar cells closer to commercialization.
基金financially supported by the National Natural Science Funds for Distinguished Young Scholar(51725201)the National Natural Science Foundation of China(51972111,51902185,51602103)+4 种基金Young Elite Scientists Sponsorship Program by CAST(2017QNRC001)International(Regional)Cooperation and Exchange Projects of the National Natural Science Foundation of China(51920105003)Innovation Program of Shanghai Municipal Education Commission(E00014)the Fundamental Research Funds for the Central Universities(JKD012016025,JKD012016022)Shanghai Engineering Research Center of Hierarchical Nanomaterials(18DZ2252400)。
文摘A controllable crystallization is of practical importance to produce high-quality perovskite thin films with reduced structural defects.Lewis bases as electron-pair donor chemicals can strongly coordinate to lead ions and have been extensively employed to manipulate the growth of perovskite crystals.In this work,we demonstrate a series of Lewis-base amides,for morphological regulation of methylammonium lead triiodide(MAPbI3)thin films.The screened acetamide was demonstrated to decently improve the grain size,along with a spatial distribution at grain boundaries(GBs).The mesostructured solar cells of acetamide-modified absorbers yielded an optimized power conversion efficiency(PCE)of 20.04%with a mitigated open-circuit voltage(V_(OC))deficit of 0.39 V.This work provides a facile and cost-effective strategy toward controllable fabrication of high-performance MAPbI3 solar cells.
文摘Aromatic bromides are important chemicals in nature and chemical industries.However,their tra‐ditional synthesis routes suffer from low atomic economy and pollutant formation.Herein,we show that organic-inorganic hybrid perovskite methylammonium lead bromide(MAPbBr_(3))nanocrystals stabilized in aqueous HBr solution can achieve simultaneous aromatic bromination and hydrogen evolution using HBr as the bromine source under visible light irradiation.By hybridizing MAPbBr_(3) with Pt/Ta_(2)O_(5) and poly(3,4‐ethylenedioxythiophene)polystyrene sulfonate as electron‐and hole‐transporting motifs,aromatic bromides were achieved from aromatic compounds with high yield(up to 99%)and selectivity(up to 99%)with the addition of N,N‐dimethylformamide or its analogs.The mechanistic studies revealed that the bromination proceeds via an electrophilic attack pathway and that HOBr may be the key intermediate in the bromination reaction.
基金Project supported by the National Natural Science Foundation of China (Grant No. 11974257)the Distinguished Young Talent Funding of Jiangsu Province, China (Grant No. BK20200003)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘Defect levels in semiconductor band gaps play a crucial role in functionalized semiconductors for practical applications in optoelectronics;however,first-principle defect calculations based on exchange-correlation functionals,such as local density approximation,grand gradient approximation(GGA),and hybrid functionals,either underestimate band gaps or misplace defect levels.In this study,we revisited iodine defects in CH_(3)NH_(3)PbI_(3) by combining the accuracy of total energy calculations of GGA and single-electron level calculation of the GW method.The combined approach predicted neutral Im_(i) to be unstable and the transition level of Im_(i)(+1/-1)to be close to the valence band maximum.Therefore,Im_(i) may not be as detrimental as previously reported.Moreover,Vm I may be unstable in the-1 charged state but could still be detrimental owing to the deep transition level of Vm I(+1/0).These results could facilitate the further understanding of the intrinsic point defect and defect passivation observed in CH_(3)NH_(3)PbI_(3).
基金financial support from the Development and Promotion of Science and Technology Talent Project(DPST) and Graduate School,Chiang Mai University
文摘Efficiency enhancement of Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) solar cell devices was performed by using iso-butyl ammonium iodide(IBA)passivated on Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) films.The n-i-p structure of perovskite solar cell devices was fabricated with the structure of FTO/SnO_(2)/Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3)(FTO,i.e.,fluorine doped tin oxide)and IBA/Spiro-OMeTAD/Ag.The effect of different weights of IBA passivated on Cs-doped perovskite solar cells(PSCs)was systematically investigated and compared with non-passivated devices.It was found that the 5-mg IBA-passivated devices exhibited a high power conversion efficiency(PCE)of 15.49%higher than 12.64%of non-IBA-passivated devices.The improvement of photovoltaic parameters of the 5-mg IBA-passivated device can be clearly observed compared to the Cs-doped device.The better performance of the IBA-passivated device can be confirmed by the reduction of PbI_(2) phase in the crystal structure,lower charge recombination rate,lower charge transfer resistance,and improved contact angle of perovskite films.Therefore,IBA passivation on Cs_(0.1)(CH_(3)NH)_(0.9)PbI_(3) is a promising technique to improve the efficiency of Cs-doped perovskite solar cells.
