Achieving high-quality perovskite films with uniform morphology and homogeneous crystallinity is challenging owing to the coffee ring effect(CRE) in the spray-coating technologies. In this study, an evaporation/spray-...Achieving high-quality perovskite films with uniform morphology and homogeneous crystallinity is challenging owing to the coffee ring effect(CRE) in the spray-coating technologies. In this study, an evaporation/spray-coating two-step deposition method is used to fabricate Cs_(0.19)FA_(0.81)PbI_(2.5)Br_(0.5)light harvesters for perovskite solar cells(PSCs). Considering the solid–liquid reaction, we establish a reaction-dependent regulating strategy that inhibits CRE successfully and prepare a high-quality perovskite layer, wherein the solvent for the FAI/Br solution during the spraying process is changed from isopropanol to n-butyl alcohol(NBA). The retarded-drying-enhanced spreading of the NBA solution inhibits contact line pinning to suppress the capillary flows and increases the reaction between metal halides(CsI/PbI_(2)) and organic salts(FAI/Br), which result in a reduction in the accumulation of solutes in the periphery effectively inhibiting CRE. Consequently, we obtain a high performance Cs_(0.19)FA_(0.81)PbI_(2.5)Br_(0.5) PSC with a power conversion efficiency(PCE) of 19.17%. An enlarged perovskite film(10 × 10 cm^(2)) containing 40 sub-cells is prepared. The average PCE of these devices is 18.33 ± 0.56%, proving the reliability of the "coffee ring" regulating strategy. This study provides an effective approach for CRE controlment in spraying technology to achieve high repeatability devices with good performance.展开更多
To the Editor Coronavirus disease 2019(COVID-19)has been around for over a year since December 2019,and the global outlook is not optimistic.Because of its high transmissibility and high mortality,management of the CO...To the Editor Coronavirus disease 2019(COVID-19)has been around for over a year since December 2019,and the global outlook is not optimistic.Because of its high transmissibility and high mortality,management of the COVID-19 pandemic has become a major challenge for health systems globally,especially for critical care.展开更多
Tin oxide has made a major breakthrough in high-efficiency perovskite solar cells(PSCs)as an efficient electron transport layer by the low-temperature chemical bath deposition method.However,tin oxide often contains p...Tin oxide has made a major breakthrough in high-efficiency perovskite solar cells(PSCs)as an efficient electron transport layer by the low-temperature chemical bath deposition method.However,tin oxide often contains pernicious defects,resulting in unsatisfactory performance.Herein,we develop high-quality tin oxide films via a nitrogen-doping strategy for high-efficiency and stable planar PSCs.The aligned energy level at the interface of doped SnO_(2)/perovskite,more excellent charge extraction and reduced nonradiative recombination contribute to the enhanced efficiency and stability.Correspondingly,the power conversion efficiency of the devices based on N‐SnO_(2) film increases to 23.41% from 20.55% of the devices based on the pristine SnO_(2).The N-SnO_(2) devices show an outstanding stability retaining 97.8% of the initial efficiency after steady-state output at a maximum power point for 600s under standard AM1.5G continuous illumination without encapsulation,while less than 50% efficiency remains for the devices based on pristine SnO_(2).This simple scalable strategy has shown great promise toward highly efficient and stable PSCs.展开更多
2,2’,7,7’-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9’-spirobifluorene(spiro-OMeTAD),as the most commonly used hole transport material(HTM),plays a significant role in the normal structured(n-i-p)high-efficiency per...2,2’,7,7’-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9’-spirobifluorene(spiro-OMeTAD),as the most commonly used hole transport material(HTM),plays a significant role in the normal structured(n-i-p)high-efficiency perovskite solar cells(PSCs).In general,it is prepared by a halogen solvent(chlorobenzene,CBZ)and needs an ion dopant(lithium bis(trifluoromethanesulfonyl)imide,Li-TFSI)to improve its conductivity and hole mobility.However,such a halogen solvent is not environmentally friendly and the widely used LiTFSI dopant would affect the stability of PSCs.Herein,we develop a non-halogen solvent-tetrahydrofuran(THF)-prepared spiro-OMeTAD solution with a new p-type dopant,potassium bis(fluorosulfonyl)imide(K-FSI),to apply into PSCs.By this strategy,high-hole-mobility spiro-OMeTAD film is achieved.Meanwhile,the potassium ions introduced by diffusion into perovskite surface passivate the interfacial defects.Therefore,a hysteresis-free champion PSC with an efficiency of 21.02%is obtained,along with significantly improved stability against illumination and ambient conditions.This work provides a new strategy for HTMs toward hysteresis-free high-efficiency and stable PSCs by substituting dopants.展开更多
基金supported by the National Key Research and Development Program of China(2018YFB1500104)the Technological Innovation Key Project of Guangdong Province(skjtdzxrwqd2018005)the National Natural Science Foundation of China(U20A20245)。
文摘Achieving high-quality perovskite films with uniform morphology and homogeneous crystallinity is challenging owing to the coffee ring effect(CRE) in the spray-coating technologies. In this study, an evaporation/spray-coating two-step deposition method is used to fabricate Cs_(0.19)FA_(0.81)PbI_(2.5)Br_(0.5)light harvesters for perovskite solar cells(PSCs). Considering the solid–liquid reaction, we establish a reaction-dependent regulating strategy that inhibits CRE successfully and prepare a high-quality perovskite layer, wherein the solvent for the FAI/Br solution during the spraying process is changed from isopropanol to n-butyl alcohol(NBA). The retarded-drying-enhanced spreading of the NBA solution inhibits contact line pinning to suppress the capillary flows and increases the reaction between metal halides(CsI/PbI_(2)) and organic salts(FAI/Br), which result in a reduction in the accumulation of solutes in the periphery effectively inhibiting CRE. Consequently, we obtain a high performance Cs_(0.19)FA_(0.81)PbI_(2.5)Br_(0.5) PSC with a power conversion efficiency(PCE) of 19.17%. An enlarged perovskite film(10 × 10 cm^(2)) containing 40 sub-cells is prepared. The average PCE of these devices is 18.33 ± 0.56%, proving the reliability of the "coffee ring" regulating strategy. This study provides an effective approach for CRE controlment in spraying technology to achieve high repeatability devices with good performance.
文摘To the Editor Coronavirus disease 2019(COVID-19)has been around for over a year since December 2019,and the global outlook is not optimistic.Because of its high transmissibility and high mortality,management of the COVID-19 pandemic has become a major challenge for health systems globally,especially for critical care.
基金This study is financially supported by the National Key Research and Development Plan(2019YFE0107200,2017YFE0131900)National Natural Science Foundation of China(21875178,52172230,91963209)+1 种基金Fundamental Research Funds for the Central Universities(WUT:202443004)Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory(XDT2020-001,XHT2020-005).
文摘Tin oxide has made a major breakthrough in high-efficiency perovskite solar cells(PSCs)as an efficient electron transport layer by the low-temperature chemical bath deposition method.However,tin oxide often contains pernicious defects,resulting in unsatisfactory performance.Herein,we develop high-quality tin oxide films via a nitrogen-doping strategy for high-efficiency and stable planar PSCs.The aligned energy level at the interface of doped SnO_(2)/perovskite,more excellent charge extraction and reduced nonradiative recombination contribute to the enhanced efficiency and stability.Correspondingly,the power conversion efficiency of the devices based on N‐SnO_(2) film increases to 23.41% from 20.55% of the devices based on the pristine SnO_(2).The N-SnO_(2) devices show an outstanding stability retaining 97.8% of the initial efficiency after steady-state output at a maximum power point for 600s under standard AM1.5G continuous illumination without encapsulation,while less than 50% efficiency remains for the devices based on pristine SnO_(2).This simple scalable strategy has shown great promise toward highly efficient and stable PSCs.
基金financially supported by the National Key Research and Development Plan(2019YFE0107200 and 2017YFE0131900)the National Natural Science Foundation of China(21875178 and 91963209)Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory(XHD2020-001 and XHT2020-005)。
文摘2,2’,7,7’-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9’-spirobifluorene(spiro-OMeTAD),as the most commonly used hole transport material(HTM),plays a significant role in the normal structured(n-i-p)high-efficiency perovskite solar cells(PSCs).In general,it is prepared by a halogen solvent(chlorobenzene,CBZ)and needs an ion dopant(lithium bis(trifluoromethanesulfonyl)imide,Li-TFSI)to improve its conductivity and hole mobility.However,such a halogen solvent is not environmentally friendly and the widely used LiTFSI dopant would affect the stability of PSCs.Herein,we develop a non-halogen solvent-tetrahydrofuran(THF)-prepared spiro-OMeTAD solution with a new p-type dopant,potassium bis(fluorosulfonyl)imide(K-FSI),to apply into PSCs.By this strategy,high-hole-mobility spiro-OMeTAD film is achieved.Meanwhile,the potassium ions introduced by diffusion into perovskite surface passivate the interfacial defects.Therefore,a hysteresis-free champion PSC with an efficiency of 21.02%is obtained,along with significantly improved stability against illumination and ambient conditions.This work provides a new strategy for HTMs toward hysteresis-free high-efficiency and stable PSCs by substituting dopants.
