Improving the quality of the perovskite active layer is crucial to obtaining high performance perovskite solar cells(PSCs). In this work, by introducing formic acid into the formamidinium lead iodide(FAPbI3)precursor ...Improving the quality of the perovskite active layer is crucial to obtaining high performance perovskite solar cells(PSCs). In this work, by introducing formic acid into the formamidinium lead iodide(FAPbI3)precursor solution, we managed to achieve reduced colloidal size in the solution, leading to more uniform deposition of FAPbI3 film with lower trap state density and higher carrier mobility. The solar cells based on the FAPbI3 absorber layer modified with formic acid show significantly better photovoltaic performance than that on the reference FAPbI3 film without formic acid. The device performance shows a close correlation with the colloidal size. Within the range studied from 6.7 to 1.0 nm, the smaller the colloidal size is, the higher the solar cell efficiency. More specifically, the cell efficiency is improved from17.82% for the control cell without formic acid to 19.81% when 0.764 M formic acid was used. Formic acid has also been added into a CH3NH3PbI3(MAPbI3) precursor solution, which exhibits a similar effect on the resulting MAPb I3 films and solar cells, with efficiency improved from 16.07% to 17.00%.展开更多
Interface engineering is an effective way to improve efficiency and long-term stability of perovskite solar cells(PSCs).Herein,an ionic compound tetrabutylammonium hexafluorophosphate(TP6)is adopted to passivate surfa...Interface engineering is an effective way to improve efficiency and long-term stability of perovskite solar cells(PSCs).Herein,an ionic compound tetrabutylammonium hexafluorophosphate(TP6)is adopted to passivate surface defects of the perovskite film.It is found that TP6 effectively reduced the surface defects,especially at the grain boundaries where the defects are abundant.Meanwhile,the exposed long alkyl chains and fluorine atoms in the TP6 enhanced the moisture stability of the perovskite film due to its strong hydrophobicity.In addition,the driving force of charge carrier separation and transport is increased by enlarged built-in potential.Consequently,the power conversion efficiency(PCE)of PSCs is significantly improved from 20.59% to 22.41%by increased open-circuit voltage(V_(oc))and fill factor(FF).The unencapsulated device with TP6 treatment exhibits better stability than the control device,and the PCE retains-80%of its initial PCE after 30 days under 15%-25%relative humidity in storage,while the PCE of the control device declines by more than 50%.展开更多
The defects within perovskite films are the fatal roadblock limiting the performance of perovskite solar cells(PSCs).Herein,we develop a patching strategy to obtain high quality perovskite film using bifunctional trif...The defects within perovskite films are the fatal roadblock limiting the performance of perovskite solar cells(PSCs).Herein,we develop a patching strategy to obtain high quality perovskite film using bifunctional trifuorophenylacetic acid(TFPA).Theoretical calculation and experiments reveal that the-COOH groups in TFPA effectively passivate the deep-energy-level defects of perovskite by combining with Pb clusters on the perovskite grain surfaces to enhance the efficiency of PSCs,and hydrophobic benzene groups containing fluorine in TFPA are exposed to improve the stability of PSCs.The power conversion effi-ciency(PCE)of PSCs with TFPA is enhanced from 22.95%to 24.56%.Most importantly,we successfully fabricated flexible PSCs using TFPA with the high PCE of 22.65%.The devices with TFPA maintain 93.22%of the initial efficiency MPP under continuous irradiation for 10.5 h,while the devices without TFPA only retain 82.22%of the initial efficiency under the same conditions for just 5 h.Meanwhile,the unsealed devices with TFPA hold 93.59%of the initial efficiency when stored in air for 3912 h.展开更多
基金supported by the National Key Research and Development Program of China(NO.2016YFA0202403/2017YFA0204800)the National Natural Science Foundation of China(61604091 and 61674098)+3 种基金the 111 Project(B14041)the National University Research Fund(Grant Nos.GK261001009,GK201603107)the Changjiang Scholar and Innovative Research Team(IRT_14R33)the Chinese National 1000-talent-plan program(1110010341)。
文摘Improving the quality of the perovskite active layer is crucial to obtaining high performance perovskite solar cells(PSCs). In this work, by introducing formic acid into the formamidinium lead iodide(FAPbI3)precursor solution, we managed to achieve reduced colloidal size in the solution, leading to more uniform deposition of FAPbI3 film with lower trap state density and higher carrier mobility. The solar cells based on the FAPbI3 absorber layer modified with formic acid show significantly better photovoltaic performance than that on the reference FAPbI3 film without formic acid. The device performance shows a close correlation with the colloidal size. Within the range studied from 6.7 to 1.0 nm, the smaller the colloidal size is, the higher the solar cell efficiency. More specifically, the cell efficiency is improved from17.82% for the control cell without formic acid to 19.81% when 0.764 M formic acid was used. Formic acid has also been added into a CH3NH3PbI3(MAPbI3) precursor solution, which exhibits a similar effect on the resulting MAPb I3 films and solar cells, with efficiency improved from 16.07% to 17.00%.
基金funded by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA17040506)the National Key Research and Development Program of China (2017YFA0204800/2016YFA0202403)+6 种基金the Key Program project of the National Natural Science Foundation of China (51933010)the National Natural Science Foundation of China (61974085)the 111 Project (B21005)the Changjiang Scholars and Innovative Research Team (IRT_14R33)the National University Research Fund (GK201903051)the Research Start-up Fund from Shaanxi Normal University (1110020142)the Shanxi Science and Technology Department (20201101012).
文摘Interface engineering is an effective way to improve efficiency and long-term stability of perovskite solar cells(PSCs).Herein,an ionic compound tetrabutylammonium hexafluorophosphate(TP6)is adopted to passivate surface defects of the perovskite film.It is found that TP6 effectively reduced the surface defects,especially at the grain boundaries where the defects are abundant.Meanwhile,the exposed long alkyl chains and fluorine atoms in the TP6 enhanced the moisture stability of the perovskite film due to its strong hydrophobicity.In addition,the driving force of charge carrier separation and transport is increased by enlarged built-in potential.Consequently,the power conversion efficiency(PCE)of PSCs is significantly improved from 20.59% to 22.41%by increased open-circuit voltage(V_(oc))and fill factor(FF).The unencapsulated device with TP6 treatment exhibits better stability than the control device,and the PCE retains-80%of its initial PCE after 30 days under 15%-25%relative humidity in storage,while the PCE of the control device declines by more than 50%.
基金supported by the key project of the National Natural Science Foundation of China(U21A20102)the 111 Project(B21005)+1 种基金the National Natural Science Foundation of China(62174103)the National University Research Fund(GK202103108)。
基金111 Project,Grant/Award Number:B14041Fundamental Research Funds for the Central Universities,Grant/Award Num bers:GK202103106,GK202103113+6 种基金Innovative Research Team,Grant/Award Number:IRT_14R33National Natural Science Foundation of China,Grant/Award Number:61975106National Universi ty Research Fund,Grant/Award Number:GK 261001009ShanXi Science and Technology Department,Grant/Award Number:20201101012Strategic Prionity Research Program of Chinese Academy of Sciences,Grant/Award Number:XDA17040506Key project of N ational Natural Science Foundation of China,Grant/Award Number:U21A20102National Natural Science Foundation of China,Grant/.Award Num ber.62174103。
文摘The defects within perovskite films are the fatal roadblock limiting the performance of perovskite solar cells(PSCs).Herein,we develop a patching strategy to obtain high quality perovskite film using bifunctional trifuorophenylacetic acid(TFPA).Theoretical calculation and experiments reveal that the-COOH groups in TFPA effectively passivate the deep-energy-level defects of perovskite by combining with Pb clusters on the perovskite grain surfaces to enhance the efficiency of PSCs,and hydrophobic benzene groups containing fluorine in TFPA are exposed to improve the stability of PSCs.The power conversion effi-ciency(PCE)of PSCs with TFPA is enhanced from 22.95%to 24.56%.Most importantly,we successfully fabricated flexible PSCs using TFPA with the high PCE of 22.65%.The devices with TFPA maintain 93.22%of the initial efficiency MPP under continuous irradiation for 10.5 h,while the devices without TFPA only retain 82.22%of the initial efficiency under the same conditions for just 5 h.Meanwhile,the unsealed devices with TFPA hold 93.59%of the initial efficiency when stored in air for 3912 h.
