A decline in atmospheric oxygen concentration is projected in the 21st century given the background of global warming.The Qinghai-Tibetan Plateau is located at a high altitude,and thus,it faces a hypoxia challenge;how...A decline in atmospheric oxygen concentration is projected in the 21st century given the background of global warming.The Qinghai-Tibetan Plateau is located at a high altitude,and thus,it faces a hypoxia challenge;however,knowledge of the factors contributing to its atmospheric oxygen concentration is still lacking.Here,we conducted joint observations of ecosystem oxygen production and carbon sinks and near-surface atmospheric oxygen concentrations on the Qinghai-Tibetan Plateau and meteorological elements at Beijing Fangshan Station.Using seasonal differences and statistical methods,we calculated the relative contribution rates of vegetation to changes in atmospheric oxygen concentration.Our results indicate that solar radiation,atmospheric humidity,and ecosystem oxygen consumption and production have a significant impact on the atmospheric oxygen concentration,and the impact shows temporal and spatial differences.Vegetation significantly impacts the oxygen concentration,with a contribution rate of 16.7%–24.5%,which is underestimated in existing research.Our findings provide important insights into the factors that influence atmospheric oxygen concentration and highlight the contribution of vegetation.To better understand the oxygen dynamics of the Qinghai-Tibetan Plateau,we recommend further field observations of soil respiration and vegetation photosynthesis to clarify the contributions of carbon storage,carbon sinks and other factors to the near-surface atmospheric oxygen concentration.展开更多
Recent advances in non-fullerene acceptors(NFAs)like Y6 have pushed the power conversion efficiencies(PCEs)of organic solar cells(OSCs)above 19%.However,the harsh fabrication conditions,such as the use of the highly v...Recent advances in non-fullerene acceptors(NFAs)like Y6 have pushed the power conversion efficiencies(PCEs)of organic solar cells(OSCs)above 19%.However,the harsh fabrication conditions,such as the use of the highly volatile chloroform(CF)solvent and the thermal annealing process,are not suitable for large-area printing technologies and environmental standards.Here,a series of vip molecules,BT2O,BTO,and BT4O,are designed and synthesized with different numbers of oligo ethylene glycol(OEG)repeating units in side chains.All these vip molecules could tune the crystallization kinetics of the annealing-free host-vip active layers by inducing the self-assembly of Y6 in non-halogenated paraxylene(PX)solution.The increasing number of OEG repeating units in vip molecules could enhance the molecular assembly ability but molecular stacking steric hindrance simultaneously.Therefore,BTO with three OEG repeating units blended with PM6:PM7:Y6 delivers the highest PCE of 17.78%.Our results demonstrate controlling the crystallization kinetics via delicate side-chain engineering of vip molecules is an effective way to achieve efficient OSCs in non-halogenated solution.展开更多
Perovskite solar cells(pero-SCs)performance is essentially limited by severe non-radiative losses and ion migration.Although numerous strategies have been proposed,challenges remain in the basic understanding of their...Perovskite solar cells(pero-SCs)performance is essentially limited by severe non-radiative losses and ion migration.Although numerous strategies have been proposed,challenges remain in the basic understanding of their origins.Here,we report a dielectric-screening-enhancement effect for perovskite defects by using organic semiconductors with finely tuned molecular structures from the atoms level.Our method produced various perovskite films with high dielectric constant values,reduced charge capture regions,suppressed ion migration,and it provides an efficient charge transport pathway for suppressing non-radiative recombination beyond the passivation effect.The resulting pero-SCs showed a promising power conversion efficiency(PCE)of 23.35%with a high open-circuit voltage(1.22 V);and the 1-cm^(2) pero-SCs maintained an excellent PCE(21.93%),showing feasibility for scalable fabrication.The robust operational and thermal stabilities revealed that this method paved a new way to understand the degradation mechanism of pero-SCs,promoting the efficiency,stability and scaled fabrication of the pero-SCs.展开更多
The power conversion efficiencies(PCEs)of all-polymer solar cells(all-PSCs),usually processed from low-boiling-point and toxic sol-vents,have reached high values of 18%.However,poor miscibility and uncontrollable crys...The power conversion efficiencies(PCEs)of all-polymer solar cells(all-PSCs),usually processed from low-boiling-point and toxic sol-vents,have reached high values of 18%.However,poor miscibility and uncontrollable crystallinity in polymer blends lead to a nota-ble drop in the PCEs when using green solvents,limiting the practical development of all-PSCs.Herein,a third component(vip)BTO was employed to optimize the miscibility and enhance the crystallinity of PM6/PY2Se-F host film processed from green solvent toluene(TL),which can effectively suppress the excessive aggregation of PY2Se-F and facilitate a nano-scale interpenetrating net-work morphology for exciton dissociation and charge transport.As a result,TL-processed all-polymer hosted solar cells(all-PHSCs)exhibited an impressive PCE of 17.01%.Moreover,the strong molecular interaction between the host and vip molecules also en-hances the thermal stability of the devices.Our host-vip strategy provides a unique approach to developing high-efficiency and stable all-PHSCs processed from green solvents,paving the way for the industrial development of all-PHSCs.展开更多
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(Grant Nos.2019QZKK0606&2019QZKK0906)。
文摘A decline in atmospheric oxygen concentration is projected in the 21st century given the background of global warming.The Qinghai-Tibetan Plateau is located at a high altitude,and thus,it faces a hypoxia challenge;however,knowledge of the factors contributing to its atmospheric oxygen concentration is still lacking.Here,we conducted joint observations of ecosystem oxygen production and carbon sinks and near-surface atmospheric oxygen concentrations on the Qinghai-Tibetan Plateau and meteorological elements at Beijing Fangshan Station.Using seasonal differences and statistical methods,we calculated the relative contribution rates of vegetation to changes in atmospheric oxygen concentration.Our results indicate that solar radiation,atmospheric humidity,and ecosystem oxygen consumption and production have a significant impact on the atmospheric oxygen concentration,and the impact shows temporal and spatial differences.Vegetation significantly impacts the oxygen concentration,with a contribution rate of 16.7%–24.5%,which is underestimated in existing research.Our findings provide important insights into the factors that influence atmospheric oxygen concentration and highlight the contribution of vegetation.To better understand the oxygen dynamics of the Qinghai-Tibetan Plateau,we recommend further field observations of soil respiration and vegetation photosynthesis to clarify the contributions of carbon storage,carbon sinks and other factors to the near-surface atmospheric oxygen concentration.
基金supported by the National Natural Science Foundation of China(Grant Nos.51922074,22075194,51820105003,and 52203233)the National Key Research and Development Program of China(Grant No.2020YFB1506400)+4 种基金the Natural Science Foundation of the Jiangsu Higher Education Insti-tutions of China(Grant No.20KJA430010)the Tang Scholar,the Priority Academic Program Development of Jiangsu Higher Educa-tion Institutions(PAPD)the National Postdoctoral Program for Innovative Talents(Grant Nos.BX2021205 and BX20220221)project funded by China Postdoctoral Science Foundation(Grant No.2022M710102)Collaborative Innovation Center of Suzhou Nano Science and Technology.
文摘Recent advances in non-fullerene acceptors(NFAs)like Y6 have pushed the power conversion efficiencies(PCEs)of organic solar cells(OSCs)above 19%.However,the harsh fabrication conditions,such as the use of the highly volatile chloroform(CF)solvent and the thermal annealing process,are not suitable for large-area printing technologies and environmental standards.Here,a series of vip molecules,BT2O,BTO,and BT4O,are designed and synthesized with different numbers of oligo ethylene glycol(OEG)repeating units in side chains.All these vip molecules could tune the crystallization kinetics of the annealing-free host-vip active layers by inducing the self-assembly of Y6 in non-halogenated paraxylene(PX)solution.The increasing number of OEG repeating units in vip molecules could enhance the molecular assembly ability but molecular stacking steric hindrance simultaneously.Therefore,BTO with three OEG repeating units blended with PM6:PM7:Y6 delivers the highest PCE of 17.78%.Our results demonstrate controlling the crystallization kinetics via delicate side-chain engineering of vip molecules is an effective way to achieve efficient OSCs in non-halogenated solution.
基金supported by the National Key Research and Development Program of China(2020YFB1506400)the National Natural Science Foundation of China(51922074,22075194,and 51820105003)+3 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(20KJA430010)the Tang Scholarthe Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Collaborative Innovation Center of Suzhou Nano Science and Technology。
文摘Perovskite solar cells(pero-SCs)performance is essentially limited by severe non-radiative losses and ion migration.Although numerous strategies have been proposed,challenges remain in the basic understanding of their origins.Here,we report a dielectric-screening-enhancement effect for perovskite defects by using organic semiconductors with finely tuned molecular structures from the atoms level.Our method produced various perovskite films with high dielectric constant values,reduced charge capture regions,suppressed ion migration,and it provides an efficient charge transport pathway for suppressing non-radiative recombination beyond the passivation effect.The resulting pero-SCs showed a promising power conversion efficiency(PCE)of 23.35%with a high open-circuit voltage(1.22 V);and the 1-cm^(2) pero-SCs maintained an excellent PCE(21.93%),showing feasibility for scalable fabrication.The robust operational and thermal stabilities revealed that this method paved a new way to understand the degradation mechanism of pero-SCs,promoting the efficiency,stability and scaled fabrication of the pero-SCs.
基金supported by the National Natural Science Foundation of China(Grant Nos.52273188,22075194,51820105003,52203233)the National Key Research and Development Program of China(Grant No.2020YFB1506400)+3 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant No.20KJA430010)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),the National Postdoctoral Program forInnovative Talents(Grant Nos.BX2021205,BX20220221)project funded by China Postdoctoral Science Foundation(Grant No.2022M710102)Collaborative Innovation Center of Suzhou Nano Science and Technology,and the Key Laboratory of Polymeric Materials Design and Synthesis for Biomedical Function,Soochow University.
文摘The power conversion efficiencies(PCEs)of all-polymer solar cells(all-PSCs),usually processed from low-boiling-point and toxic sol-vents,have reached high values of 18%.However,poor miscibility and uncontrollable crystallinity in polymer blends lead to a nota-ble drop in the PCEs when using green solvents,limiting the practical development of all-PSCs.Herein,a third component(vip)BTO was employed to optimize the miscibility and enhance the crystallinity of PM6/PY2Se-F host film processed from green solvent toluene(TL),which can effectively suppress the excessive aggregation of PY2Se-F and facilitate a nano-scale interpenetrating net-work morphology for exciton dissociation and charge transport.As a result,TL-processed all-polymer hosted solar cells(all-PHSCs)exhibited an impressive PCE of 17.01%.Moreover,the strong molecular interaction between the host and vip molecules also en-hances the thermal stability of the devices.Our host-vip strategy provides a unique approach to developing high-efficiency and stable all-PHSCs processed from green solvents,paving the way for the industrial development of all-PHSCs.
