Although lots of efforts have been devoted on new less hygroscopic dopants to address problems in hole transport materials(HTM),the long-time post-oxidation and the volatilization of 4-tert-butylpyridine(tBP)are still...Although lots of efforts have been devoted on new less hygroscopic dopants to address problems in hole transport materials(HTM),the long-time post-oxidation and the volatilization of 4-tert-butylpyridine(tBP)are still issues.A new doping mechanism for spiro-OMeTAD by disulfiram(TETD)is revealed in this work.Owing to its disulfide bond,TETD can be activated easily to produce reactive sulfur for the rapid oxidation of spiro-OMeTAD in the absence of oxygen with formation of[spiro-OMeTAD•]+[SC(S)N(C_(2)H_(5))_(2)]^(-).Thus,in this situation,the Li+ion has the opportunity to coordinate tBP and fix each other in HTM film.DFT calculations suggest that the resulting favorable energy(with a△E of−1.29 eV)must come from the mutual interactions among Li^(+),TFSI^(−),and tBP,which is different from the well-known doping process that tBP would not participate in the doping reaction.As a result,the introduction of a new radical into the HTM greatly reduce device performance fluctuations due to the environmental dependence and inhibit tBP volatilizing for enhanced long-term stability.展开更多
The exceptional photoelectric performance and high compatibility of perovskite materials render perovskite solar cells highly promising for extensive development,thus garnering significant attention.In perovskite sola...The exceptional photoelectric performance and high compatibility of perovskite materials render perovskite solar cells highly promising for extensive development,thus garnering significant attention.In perovskite solar cells,the hole transport layer plays a crucial role.For the commonly employed organic small molecule hole transport material Spiro-OMeTAD,a certain period of oxidation treatment is required to achieve complete transport performance.However,this posttreatment oxidation processes typically rely on ambient oxidation,which poses challenges in terms of precise control and leads to degradation of the perovskite light absorption layer.This approach fails to meet the demands for high efficiency and stability in practical application.Herein,the mechanism of ultrafast laser on Spiro-OMeTAD and the reaction process for laser-induced oxidation of it are investigated.PbI_(2) at Perovskite/Spiro-OMeTAD interface breaks down to produce I_(2) upon ultrafast laser irradiation and I_(2) promote the oxidation process.Through the laser irradiation oxidation processing,a higher stability of perovskite solar cells is achieved.This work establishes a new approach toward oxidation treatment of Spiro-OMeTAD.展开更多
Hole transporting materials(HTMs)play an unparalleled role in heightening the stability and photovoltaic performance of perovskite solar cells(PSCs).The organic small molecule spiro-OMeTAD is frequently utilized for H...Hole transporting materials(HTMs)play an unparalleled role in heightening the stability and photovoltaic performance of perovskite solar cells(PSCs).The organic small molecule spiro-OMeTAD is frequently utilized for HTM in PSCs.However,the raw spiro-OMeTAD without dopant would be harmful to the development of highly efficient PSCs,due to its unsatisfied hole mobility and conductivity.Therefore,we introduce an inorganic dopant(chromium trioxide,CrO_(3))into the lithium-salt doped spiro-OMeTAD.Because of the exclamatory oxidizability of CrO_(3),it can accelerate the oxidation of spiro-OMeTAD and thereby enhancing the hole mobility of HTM.The introduction of CrO_(3) not only substantially decreases the density of defects,but also adjusts spiro-OMeTAD energy band,and thus effectively suppresses the hysteresis and improving stability of PSCs.In the end,we obtained a power conversion efficiency(PCE)as high as 22.6%after doping CrO_(3) in spiro-OMeTAD.The facile,low cost and outstanding photovoltaic performance render CrO_(3) an excellent dopant for HTMs in PSCs.展开更多
Lithium bis(trifluoromethanesulfonyl)imide(Li-TFSI)/4-tert-butylpyridine(tBP)is a classic doping system for the hole transport material Spiro-OMeTAD in typical n-i-p structure perovskite solar cells(PSCs),but this sys...Lithium bis(trifluoromethanesulfonyl)imide(Li-TFSI)/4-tert-butylpyridine(tBP)is a classic doping system for the hole transport material Spiro-OMeTAD in typical n-i-p structure perovskite solar cells(PSCs),but this system will cause many problems such as high hygroscopicity,Li+migration,pinholes and so on,which hinder PSC from maintaining high efficiency and stability for long-term.In this work,an effective strategy is demonstrated to improve the performance and stability of PSC by replacing t BP with 12-crown-4.The chelation of 12-crown-4 with Li+not only improves the doping effect of Li-TFSI,but also perfectly solves the problems caused by the Li-TFSI/tBP system.The PSC based on this strategy achieved a champion power conversion efficiency(PCE)over 21%,which is significantly better than the pristine device(19.37%).More importantly,the without encapsulated device based on Li-TFSI/12-crown-4 still maintains 87%of the initial PCE even after 60 days exposure in air,while the pristine device only maintains 22%of the initial PCE under the same aging conditions.This strategy paves a novel way for constructing efficient and stable PSCs.展开更多
Lithium salt-based hole transport layer(HTL)dopants commonly used in perovskite solar cells(PSCs)are known to negatively impact stability due to their intrinsic hygroscopic properties and ion migration.In this study,w...Lithium salt-based hole transport layer(HTL)dopants commonly used in perovskite solar cells(PSCs)are known to negatively impact stability due to their intrinsic hygroscopic properties and ion migration.In this study,we introduce an ammonium salt,p-methoxyphenylethylamine bis(trifluoromethyl)sulfoni mide(MPT),as a novel dual-function dopant for the HTL in PSCs.The chemical interaction between MPT and the widely used HTL material spiro-OMeTAD generates high concentrations of spiroOMeTAD^(+)radicals,effectively enhancing the doping of spiro-OMeTAD.Additionally,MPT reacts with the perovskite layer,forming a 2D perovskite structure at the perovskite/HTL interface,which passivates defects and suppresses interfacial ion migration.As a result,PSCs with MPT doping achieved a remarkable power conversion efficiency(PCE)of 25.52%for small-area devices(0.045 cm^(2))and 21.01%for mini-modules(16.8 cm^(2)).Moreover,the incorporation of MPT significantly enhances the moisture,light,and thermal stability of the PSCs by eliminating Li^(+)and suppressing I-migration.Notably,PSCs with MPT-doped PTAA retained 84%of their initial PCE after 1,300 h of aging at 60℃in a nitrogen-filled glovebox.Our work presents a unique doping strategy for the HTL in PSCs,offering a promising approach to simultaneously improve both the stability and efficiency of these devices.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 ...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
To ensure the infiltration of spiro-OMeTAD into the quantum dot-sensitized photoanode and to consider the limit of the hole diffusion length in the spiro-OMeTAD layer, a rutile TiO2 nanorod array with a length of 200 ...To ensure the infiltration of spiro-OMeTAD into the quantum dot-sensitized photoanode and to consider the limit of the hole diffusion length in the spiro-OMeTAD layer, a rutile TiO2 nanorod array with a length of 200 nm, a diameter of 20 nm and an areal density of 720 ram 2 was successfully prepared using a hydrothermal method with an aqueous-grown solution of 38 mM titanium isopropoxide and 6 M hydrochloric acid at 170 ℃ for 75 min. PbS quantum dots were deposited by a spin coating-assisted successive ionic layer adsorption and reaction （spin-SILAR）, and all solid-state PbS quantum dot-sensitized TiO2 nanorod array solar cells were fabricated using spiro-OMeTAD as electrolytes. The results revealed that the average crystal size of PbS quantum dots was -78 nm using Pb（NO3）2 as the lead source and remain unchanged with the increase of the number of spin-SILAR cycles. The all solid-state PbS quantum dot-sensitized TiO2 nanorod array solar cells with spin-SILAR cycle numbers of 20, 30 and 40 achieved the photoelectric conversion efficiencies of 3.74%, 4.12% and 3.11%, respectively, under AM 1.5 G illumination （100 mW/cm2）.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52001066,21805039,22375045,22373015 and 22271046)the Natural Science Foundation of Fujian Province(No.2023J01500)Young teacher training program of Fujian Normal University(No.SDPY2023013).
文摘Although lots of efforts have been devoted on new less hygroscopic dopants to address problems in hole transport materials(HTM),the long-time post-oxidation and the volatilization of 4-tert-butylpyridine(tBP)are still issues.A new doping mechanism for spiro-OMeTAD by disulfiram(TETD)is revealed in this work.Owing to its disulfide bond,TETD can be activated easily to produce reactive sulfur for the rapid oxidation of spiro-OMeTAD in the absence of oxygen with formation of[spiro-OMeTAD•]+[SC(S)N(C_(2)H_(5))_(2)]^(-).Thus,in this situation,the Li+ion has the opportunity to coordinate tBP and fix each other in HTM film.DFT calculations suggest that the resulting favorable energy(with a△E of−1.29 eV)must come from the mutual interactions among Li^(+),TFSI^(−),and tBP,which is different from the well-known doping process that tBP would not participate in the doping reaction.As a result,the introduction of a new radical into the HTM greatly reduce device performance fluctuations due to the environmental dependence and inhibit tBP volatilizing for enhanced long-term stability.
基金supported by the National Key Research and Development Program of China(2020YFA0715000)the Guangdong Basic and Applied Basic Research Foundation(2021B1515120041)the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(2021JJLH0058)。
文摘The exceptional photoelectric performance and high compatibility of perovskite materials render perovskite solar cells highly promising for extensive development,thus garnering significant attention.In perovskite solar cells,the hole transport layer plays a crucial role.For the commonly employed organic small molecule hole transport material Spiro-OMeTAD,a certain period of oxidation treatment is required to achieve complete transport performance.However,this posttreatment oxidation processes typically rely on ambient oxidation,which poses challenges in terms of precise control and leads to degradation of the perovskite light absorption layer.This approach fails to meet the demands for high efficiency and stability in practical application.Herein,the mechanism of ultrafast laser on Spiro-OMeTAD and the reaction process for laser-induced oxidation of it are investigated.PbI_(2) at Perovskite/Spiro-OMeTAD interface breaks down to produce I_(2) upon ultrafast laser irradiation and I_(2) promote the oxidation process.Through the laser irradiation oxidation processing,a higher stability of perovskite solar cells is achieved.This work establishes a new approach toward oxidation treatment of Spiro-OMeTAD.
基金jointly supported by the National Natural Science Foundation of China(Nos.51972123,U1705256,61804058,21771066)the Promotion Program for Young and Middle-aged Teacher in Science and Technology Research of Huaqiao University(ZQN-706)the Cultivation Program for Postgraduate in Scientific Research Innovation Ability of Huaqiao University(No.19011081020)。
文摘Hole transporting materials(HTMs)play an unparalleled role in heightening the stability and photovoltaic performance of perovskite solar cells(PSCs).The organic small molecule spiro-OMeTAD is frequently utilized for HTM in PSCs.However,the raw spiro-OMeTAD without dopant would be harmful to the development of highly efficient PSCs,due to its unsatisfied hole mobility and conductivity.Therefore,we introduce an inorganic dopant(chromium trioxide,CrO_(3))into the lithium-salt doped spiro-OMeTAD.Because of the exclamatory oxidizability of CrO_(3),it can accelerate the oxidation of spiro-OMeTAD and thereby enhancing the hole mobility of HTM.The introduction of CrO_(3) not only substantially decreases the density of defects,but also adjusts spiro-OMeTAD energy band,and thus effectively suppresses the hysteresis and improving stability of PSCs.In the end,we obtained a power conversion efficiency(PCE)as high as 22.6%after doping CrO_(3) in spiro-OMeTAD.The facile,low cost and outstanding photovoltaic performance render CrO_(3) an excellent dopant for HTMs in PSCs.
基金the National Natural Science Foundation of China(22175029 and 62104031)the Sichuan Science and Technology Program(2019YJ0162)+3 种基金the Open Foundation of State Key Laboratory of Electronic Thin Films and Integrated Devices(KFJJ202109)the Natural Science Foundation of Shenzhen Innovation Committee(JCYJ20210324135614040)the Technical Field Funds of 173 Project(2021-JCJQ-JJ-0663)the Fundamental Research Funds for the Central Universities of China(ZYGX2021J010 and Y030202059018023)for financial support。
文摘Lithium bis(trifluoromethanesulfonyl)imide(Li-TFSI)/4-tert-butylpyridine(tBP)is a classic doping system for the hole transport material Spiro-OMeTAD in typical n-i-p structure perovskite solar cells(PSCs),but this system will cause many problems such as high hygroscopicity,Li+migration,pinholes and so on,which hinder PSC from maintaining high efficiency and stability for long-term.In this work,an effective strategy is demonstrated to improve the performance and stability of PSC by replacing t BP with 12-crown-4.The chelation of 12-crown-4 with Li+not only improves the doping effect of Li-TFSI,but also perfectly solves the problems caused by the Li-TFSI/tBP system.The PSC based on this strategy achieved a champion power conversion efficiency(PCE)over 21%,which is significantly better than the pristine device(19.37%).More importantly,the without encapsulated device based on Li-TFSI/12-crown-4 still maintains 87%of the initial PCE even after 60 days exposure in air,while the pristine device only maintains 22%of the initial PCE under the same aging conditions.This strategy paves a novel way for constructing efficient and stable PSCs.
基金supported by the National Natural Science Foundation of China(52172238,52102304,51902264)Open Project of Shaanxi Laboratory of Aerospace Power(2021SXSYS-01-03)the Fundamental Research Funds for the Central Universities(3102019JC0005)。
文摘Lithium salt-based hole transport layer(HTL)dopants commonly used in perovskite solar cells(PSCs)are known to negatively impact stability due to their intrinsic hygroscopic properties and ion migration.In this study,we introduce an ammonium salt,p-methoxyphenylethylamine bis(trifluoromethyl)sulfoni mide(MPT),as a novel dual-function dopant for the HTL in PSCs.The chemical interaction between MPT and the widely used HTL material spiro-OMeTAD generates high concentrations of spiroOMeTAD^(+)radicals,effectively enhancing the doping of spiro-OMeTAD.Additionally,MPT reacts with the perovskite layer,forming a 2D perovskite structure at the perovskite/HTL interface,which passivates defects and suppresses interfacial ion migration.As a result,PSCs with MPT doping achieved a remarkable power conversion efficiency(PCE)of 25.52%for small-area devices(0.045 cm^(2))and 21.01%for mini-modules(16.8 cm^(2)).Moreover,the incorporation of MPT significantly enhances the moisture,light,and thermal stability of the PSCs by eliminating Li^(+)and suppressing I-migration.Notably,PSCs with MPT-doped PTAA retained 84%of their initial PCE after 1,300 h of aging at 60℃in a nitrogen-filled glovebox.Our work presents a unique doping strategy for the HTL in PSCs,offering a promising approach to simultaneously improve both the stability and efficiency of these devices.
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.
基金supported by the National Natural Science Foundation of China(51272061,51472071)
文摘To ensure the infiltration of spiro-OMeTAD into the quantum dot-sensitized photoanode and to consider the limit of the hole diffusion length in the spiro-OMeTAD layer, a rutile TiO2 nanorod array with a length of 200 nm, a diameter of 20 nm and an areal density of 720 ram 2 was successfully prepared using a hydrothermal method with an aqueous-grown solution of 38 mM titanium isopropoxide and 6 M hydrochloric acid at 170 ℃ for 75 min. PbS quantum dots were deposited by a spin coating-assisted successive ionic layer adsorption and reaction （spin-SILAR）, and all solid-state PbS quantum dot-sensitized TiO2 nanorod array solar cells were fabricated using spiro-OMeTAD as electrolytes. The results revealed that the average crystal size of PbS quantum dots was -78 nm using Pb（NO3）2 as the lead source and remain unchanged with the increase of the number of spin-SILAR cycles. The all solid-state PbS quantum dot-sensitized TiO2 nanorod array solar cells with spin-SILAR cycle numbers of 20, 30 and 40 achieved the photoelectric conversion efficiencies of 3.74%, 4.12% and 3.11%, respectively, under AM 1.5 G illumination （100 mW/cm2）.
