The photovoltaic performance of perovskite sloar cells(PSCs)is strongly dependent on the crystallinity,morphorlogy and defects of perovskite films.In the present work,a novel strategy was developed to fabricate the hi...The photovoltaic performance of perovskite sloar cells(PSCs)is strongly dependent on the crystallinity,morphorlogy and defects of perovskite films.In the present work,a novel strategy was developed to fabricate the high quality CsPbI3 inorganic perovskite by tuning the growth dynamics of CsPbI3 by pretreatment of fresh CsPbI3 films with phenylethylamine iodide(PEAI).The PEAI can mediate the phase transformation from 1D(DMAPbI3)(DMA:dimethylammonium)to 3D CsPbI3 all-inorganic perovskite films via the PEA2CsPb2I7 of 2D perovskite intermediate phase,resulting in highly crystalline CsPbI3 perovskite films with remarkably enlarged grains and reduced defects.The as-achieved highly crystalline CsPbI3 inorganic perovskite not only exhibited improved phase stability but also significant reduced defects.The perovskite solar cells based on these CsPbI3 thin films exhibited a champion efficiency of 17.08%,much higher than those prepared through posttreatment or direct addition of PEAI into CsPbI3 precursor solution.This work not only developed an effective strategy to prepare high crystalline CsPbI3 film and highly efficient CsPbI3-based all-inorganic PSCs,but also unraveled the mediation mechanism of CsPbI3by pre-treatment of PEAI,shedding light for further development of high perfomance perovskite-based optoelectronics.展开更多
FA-Cs mixed-cation perovskite has been reported as a promising candidate for obtaining highly efficient and stable photovoltaic devices.Phenylethylamine iodide(PEAI)post-treatment is a widely used and effective method...FA-Cs mixed-cation perovskite has been reported as a promising candidate for obtaining highly efficient and stable photovoltaic devices.Phenylethylamine iodide(PEAI)post-treatment is a widely used and effective method for surface passivation of FA-Cs perovskite layer in devices.However,it is still controversial whether the PEAI post-treatment would form two-dimensional(2D)perovskite PEA_(2)PbI_(4) capping layer or just result in PEA+terminated surface.Here in this work,the function of PEAI post-treatment on FA-Cs mixed-cation perovskite FA_(1-x)Cs_(x)PbI_(3)(x=0.1–0.9)with varied Cs contents is elucidated.With increased Cs content,the FA-Cs perovskite shows higher resistance to the cation exchange between FA+and PEA+.This Cs-content-dependent cation exchange results in the different PEAI reaction preferences with FA-Cs mixed-cation perovskites.Furthermore,higher Cs content with stronger resistance to cation exchange reaction leads to a wider processing window for post-treatment and defect passivation,which is beneficial for the fabrication of large-scale photovoltaic devices.展开更多
G2 pea exhibits an apical senescence delaying phenotype under short-day （SD） conditions; however, the structural basis for its apical development is still largely unknown. In the present study, the apical meristem o...G2 pea exhibits an apical senescence delaying phenotype under short-day （SD） conditions; however, the structural basis for its apical development is still largely unknown. In the present study, the apical meristem of SD-grown G2 pea plants underwent a transition from vegetative to indeterminate inflorescence meristem, but the apical meristem of long-day （LD）-grown G2 pea plants would be further converted to determinate floral meristem. Both SD signal and GA3 treatment enhanced expression of the putative calcium transporter PPF1, and pea homologs of TFL1 （LF and DET）, whereas LD signal suppressed their expression at 60 d post-flowering compared with those at 40 d post-flowering. Both PPF1 and LF expressed at the vegetative and reproductive phases in SD-grown apical buds, but floral initiation obviously increased the expression level of PPF1 compared with the unchanged expression level of LF from 40 to 60 d post-flowering. In addition, although the floral initiation significantly enhanced the expression levels of PPF1 and DET, DET was mainly expressed after floral initiation in SD-grown apil buds. Therefore, the main structural difference between LD- and SD-grown apical meristem in G2 pea lies in whether their apical indeterminate inflorescence meristem could be converted to the determinate structure.展开更多
The AAIR genomic DNA of G2 pea (Pisum sativum L.) was amplified by PCR method. Sequence analysis showed that it was composed of 8 introns and 9 exons with three of the introns containing specific A/T-rich endogenous p...The AAIR genomic DNA of G2 pea (Pisum sativum L.) was amplified by PCR method. Sequence analysis showed that it was composed of 8 introns and 9 exons with three of the introns containing specific A/T-rich endogenous promoter regions. Molecular hybridization experiments revealed that the expression of AAIR remained at a high level before and after flowering if grown in short day growth chambers. However, when grown under long day conditions, the level of AAIR expression declined very rapidly after flowering. This variation of AAIR expression is consistent with the change of enzymatic activity of acetohydroxy acid isomeroreductase. Functional complementation experiments carried out using an acetohydroxy acid isomeroreductase deficient E. coli strain showed that these cells could not grow on M9 medium without addition of branched-chain amino acids unless they were transformed with the AAIR expression vector. Further study revealed that overexpression of the pea AAIR cDNA in acetohydroxy acid isomeroreductase deficient E. coli strain enhanced significantly its branched-chain amino acid biosynthetic capacity. Results from gel shift experiments showed that fractions of pea nuclear protein extracts could bind specifically to some A/T rich regions present in introns of the AAIR gene. The A/T-rich-region-binding proteins remained at a steady level in the non-senescing apical buds of short-day grown G2 pea. In the rapid-senescing apical buds of long-day grown G2 pea, the levels of these proteins declined rapidly after flower initiation. Therefore, the nuclear protein binding capacities to endogenous promoter regions may constitute an important mechanism to regulate AAIR gene expression.展开更多
基金supported by the National Natural Science Foundation of China(No.51602106)。
文摘The photovoltaic performance of perovskite sloar cells(PSCs)is strongly dependent on the crystallinity,morphorlogy and defects of perovskite films.In the present work,a novel strategy was developed to fabricate the high quality CsPbI3 inorganic perovskite by tuning the growth dynamics of CsPbI3 by pretreatment of fresh CsPbI3 films with phenylethylamine iodide(PEAI).The PEAI can mediate the phase transformation from 1D(DMAPbI3)(DMA:dimethylammonium)to 3D CsPbI3 all-inorganic perovskite films via the PEA2CsPb2I7 of 2D perovskite intermediate phase,resulting in highly crystalline CsPbI3 perovskite films with remarkably enlarged grains and reduced defects.The as-achieved highly crystalline CsPbI3 inorganic perovskite not only exhibited improved phase stability but also significant reduced defects.The perovskite solar cells based on these CsPbI3 thin films exhibited a champion efficiency of 17.08%,much higher than those prepared through posttreatment or direct addition of PEAI into CsPbI3 precursor solution.This work not only developed an effective strategy to prepare high crystalline CsPbI3 film and highly efficient CsPbI3-based all-inorganic PSCs,but also unraveled the mediation mechanism of CsPbI3by pre-treatment of PEAI,shedding light for further development of high perfomance perovskite-based optoelectronics.
基金supported by the National Key Research and Development Program of China(2017YFE0127100)the National Natural Science Foundation of China(NSFC,Grant 22025505)+1 种基金the Program of Shanghai Academic Technology Research Leader(Grant 20XD1422200)the Key Laboratory of Resource Chemistry,Ministry of Education(KLRC_ME2003)。
文摘FA-Cs mixed-cation perovskite has been reported as a promising candidate for obtaining highly efficient and stable photovoltaic devices.Phenylethylamine iodide(PEAI)post-treatment is a widely used and effective method for surface passivation of FA-Cs perovskite layer in devices.However,it is still controversial whether the PEAI post-treatment would form two-dimensional(2D)perovskite PEA_(2)PbI_(4) capping layer or just result in PEA+terminated surface.Here in this work,the function of PEAI post-treatment on FA-Cs mixed-cation perovskite FA_(1-x)Cs_(x)PbI_(3)(x=0.1–0.9)with varied Cs contents is elucidated.With increased Cs content,the FA-Cs perovskite shows higher resistance to the cation exchange between FA+and PEA+.This Cs-content-dependent cation exchange results in the different PEAI reaction preferences with FA-Cs mixed-cation perovskites.Furthermore,higher Cs content with stronger resistance to cation exchange reaction leads to a wider processing window for post-treatment and defect passivation,which is beneficial for the fabrication of large-scale photovoltaic devices.
基金Supported by the Southeast University Foundation for Excellent YoungScholars (4023001013)the Program for New Century Excellent Talentsin University.
文摘G2 pea exhibits an apical senescence delaying phenotype under short-day （SD） conditions; however, the structural basis for its apical development is still largely unknown. In the present study, the apical meristem of SD-grown G2 pea plants underwent a transition from vegetative to indeterminate inflorescence meristem, but the apical meristem of long-day （LD）-grown G2 pea plants would be further converted to determinate floral meristem. Both SD signal and GA3 treatment enhanced expression of the putative calcium transporter PPF1, and pea homologs of TFL1 （LF and DET）, whereas LD signal suppressed their expression at 60 d post-flowering compared with those at 40 d post-flowering. Both PPF1 and LF expressed at the vegetative and reproductive phases in SD-grown apical buds, but floral initiation obviously increased the expression level of PPF1 compared with the unchanged expression level of LF from 40 to 60 d post-flowering. In addition, although the floral initiation significantly enhanced the expression levels of PPF1 and DET, DET was mainly expressed after floral initiation in SD-grown apil buds. Therefore, the main structural difference between LD- and SD-grown apical meristem in G2 pea lies in whether their apical indeterminate inflorescence meristem could be converted to the determinate structure.
文摘The AAIR genomic DNA of G2 pea (Pisum sativum L.) was amplified by PCR method. Sequence analysis showed that it was composed of 8 introns and 9 exons with three of the introns containing specific A/T-rich endogenous promoter regions. Molecular hybridization experiments revealed that the expression of AAIR remained at a high level before and after flowering if grown in short day growth chambers. However, when grown under long day conditions, the level of AAIR expression declined very rapidly after flowering. This variation of AAIR expression is consistent with the change of enzymatic activity of acetohydroxy acid isomeroreductase. Functional complementation experiments carried out using an acetohydroxy acid isomeroreductase deficient E. coli strain showed that these cells could not grow on M9 medium without addition of branched-chain amino acids unless they were transformed with the AAIR expression vector. Further study revealed that overexpression of the pea AAIR cDNA in acetohydroxy acid isomeroreductase deficient E. coli strain enhanced significantly its branched-chain amino acid biosynthetic capacity. Results from gel shift experiments showed that fractions of pea nuclear protein extracts could bind specifically to some A/T rich regions present in introns of the AAIR gene. The A/T-rich-region-binding proteins remained at a steady level in the non-senescing apical buds of short-day grown G2 pea. In the rapid-senescing apical buds of long-day grown G2 pea, the levels of these proteins declined rapidly after flower initiation. Therefore, the nuclear protein binding capacities to endogenous promoter regions may constitute an important mechanism to regulate AAIR gene expression.
