Surface Reconstruction for Efficient Cs₂AgBiBr₆ Solar Cells

Lead-free double perovskite Cs2AgBiBr6 is considered to serve as a substitute for toxic lead-based perovskite components and is a promising candidate for environmentally friendly perovskite solar cells (PSCs). However, the high deep-level trap density in Cs2AgBiBr6 films hinders the device performance, which is caused by the different solubilities of components in the precursor solution and the solution-process fabrication method. In this work, we reported a surface reconstruction (SR) strategy, in which a dissolution process is initiated by dimethyl sulfoxide (DMSO) and followed by the introduction of methylammonium bromide (MABr) to generate a mixed organic–inorganic intermediate phase and induce an orderly recrystallization. The dissolution–recrystallization process effectively improves the overall crystalline quality and surface composition stoichiometry ratio, passivates the bromine vacancies enriched in the film, and forms a dense as well as ordered film surface, resulting in reduced trap density, extended carrier lifetime, better interfacial contact, and faster carrier extraction. The differences in underlying mechanisms and effects between the conventional interfacial passivation (IP) strategy based on the passivator/isopropanol (IPA) system and the SR strategy proposed in this work were also compared by multiple characterizations. All these advantages enable the Cs2AgBiBr6-based PSCs fabricated by the SR strategy to achieve a significantly higher power conversion efficiency (PCE) of 2.05% and an ultrahigh fill factor (FF) of 83.80% as well as open-circuit voltage (VOC) of 1.201 V, with good stability and broad applicability in the hole transport layer (HTL)-free PSCs. Therefore, this work points out the fundamentally different mechanisms of two post-treatment strategies on the overall regulation of Cs2AgBiBr6 films and provides a clear clue to further enhance the quality of lead-free double perovskite films and optimize the photovoltaic performance of PSCs

Table_1_Identification and Characterization of Csa-miR395s Reveal Their Involvements in Fruit Expansion and Abiotic Stresses in Cucumber.DOCX

The miR395 plays an indispensable role in biochemical processes by regulating their target genes. However, little is known about the roles of miR395 in cucumber fruit expansion and response to abiotic stresses. Here, 4 Csa-miR395s and 8 corresponding target genes were identified in the cucumber genome. Csa-miR395s were all located on the same chromosome (Chr 5). Csa-miR395a/b/c and Csa-miR395d were distributed in different branches without a closer genetic relationship. Massive cis-acting elements, including light, phytohormone, and stress response elements, were detected in the promoter regions of Csa-MIR395s, indicating that Csa-miR395s might be involved in complex regulatory networks to control cucumber growth and development and stress response. In addition, Csa-miR395a/b/c shared the same target genes, and Csa-miR395d had its specific target genes. Tissue-specific expression analysis showed that Csa-miR395a/b/c were all expressed in the leaf, root, ovary, and expanded fruit of cucumber and highly expressed in the expanded fruits compared to the ovary, while Csa2G215520 and Csa1G502860 (target genes of Csa-miR395a/b/c) presented a downregulated trend in the expanded fruit compared to the ovary. Meanwhile, the protein co-expression network revealed that these target genes had interactions in sulfur metabolism. These results suggested that Csa-miR395a/b/c targeting Csa2G215520 and Csa1G502860 might promote cucumber fruit expansion by affecting sulfur metabolism. Additionally, Quantitative Real-time PCR analysis validated that Csa-miR395s could be regulated by NaCl stress, and Csa-miR395a/b/c could respond to PEG stress, which further confirmed the reliability of cis-acting elements data. Taken together, our results could be helpful for further exploration of the functions of miR395s in cucumber fruit expansion and response to abiotic stresses.</p

Largely Enhanced Stretching Sensitivity of Polyurethane/Carbon Nanotube Nanocomposites via Incorporation of Cellulose Nanofiber

Stretchable sensors have drawn a great deal of attention due to their importance and necessity in high-technology areas. However, it is difficult to obtain sensors with high sensitivity accompanied by high tenacity. Taking advantage of the very large aspect ratio and amphiphilicity of nanofibrillated cellulose (NFC), in this study, we fabricated polyurethane (TPU)/multiwall carbon nanotube (CNT) nanocomposites with excellent dispersion using NFC as stabilizer. Then the mechanical and electrical properties, particularly the stretching sensitivity of the prepared TPU/NFC@CNTs nanocomposites, were investigated. It was found that the prepared TPU/NFC@CNTs has much better mechanical properties and electrical conductivity compared with those of TPU/CNTs composites. More importantly, a linear change of electrical conductivity as a function of stretching is observed for at least strains up to 300% and a very high sensitivity whose gauge factor close to 50 could be achieved. The excellent stretching sensitivity could be attributed to the unique role of NFC: (1) assisting the dispersion of CNTs, (2) enhancing the interaction between NFC and TPU matrix as due to its amphiphilicity, and (3) increasing the overall aspect ratio of CNTs via connecting many tiny CNTs bundled together along the long axis

Data_Sheet_1_Identification and Application of BhAPRR2 Controlling Peel Colour in Wax Gourd (Benincasa hispida).PDF

Peel color is an important factor affecting commodity quality in vegetables; however, the genes controlling this trait remain unclear in wax gourd. Here, we used two F2 genetic segregation populations to explore the inheritance patterns and to clone the genes associated with green and white skin in wax gourd. The F2 and BC1 trait segregation ratios were 3:1 and 1:1, respectively, and the trait was controlled by nuclear genes. Bulked segregant analysis of both F2 plants revealed peaks on Chr5 exceeding the confidence interval. Additionally, 6,244 F2 plants were used to compress the candidate interval into a region of 179 Kb; one candidate gene, Bch05G003950 (BhAPRR2), encoding two-component response regulator-like protein Arabidopsis pseudo-response regulator2 (APRR2), which is involved in the regulation of peel color, was present in this interval. Two bases (GA) present in the coding sequence of BhAPRR2 in green-skinned wax gourd were absent from white-skinned wax gourd. The latter contained a frameshift mutation, a premature stop codon, and lacked 335 residues required for the protein functional region. The chlorophyll content and BhAPRR2 expression were significantly higher in green-skinned than in white-skinned wax gourd. Thus, BhAPRR2 may regulate the peel color of wax gourd. This study provides a theoretical foundation for further studies of the mechanism of gene regulation for the fruit peel color of wax gourd.</p

Efficient Perovskite Solar Cells with Enhanced Thermal Stability by Sulfide Treatment

The performance degradation of perovskite solar cells (PSCs) under harsh environment (e.g., heat, moisture, light) is one of the greatest challenges for their commercialization. Herein, a conjugated sulfide 2-mercaptobenzimidazole (2MBI) is applied to significantly improve the photovoltaic properties and thermal stability of PSCs. When treated with heat, 2MBI cross-links with each other on the perovskite surface to facilitate charge transportation, suppress the escape of volatile species, and guide the rearrangement of surface perovskite grains. PSCs with 2MBI modification reach a PCE as high as 21.7% and maintain high-efficiency output during and after thermodestruction at 85 °C, while the unmodified ones suffer severe degradation. Unencapsulated devices after thermodestruction achieve over 98% of initial efficiency after 40-day storage under ambient conditions

Superstable Cs<i>_x</i>SnBr_<i>x</i>+2@CsBr Nanocrystals with Over 1200 h of Half-Value PLQY in Air

Tin-based perovskites comprise one of the preferred nontoxic alternatives to Pb-based perovskites due to their desirable optoelectronic properties. However, there remains a crucial stability problem due to the property of Sn2+ oxidation. In this study, we reported stable tin-based perovskite nanocrystals (NCs) using stannous acetate as the Sn2+ source because of its stronger Sn–O bonding. To prevent the oxidation of Sn2+, a thin layer of CsBr coverage was formed in situ; tin-based perovskite NCs, CsxSnBrx+2@CsBr (1 x < 4), show a high photoluminescence quantum yield (PLQY) of 78.2% and high stability. The measured lifetime of PLQY decrease to half of the initial value is ∼1287 h under ambient conditions and ∼2200 h under a nitrogen atmosphere, respectively. Furthermore, the as-fabricated light-emitting diodes based on CsxSnBrx+2@CsBr NCs as the emitting layer exhibit a maximum luminescence of 16 cd/m2 and an external quantum efficiency of 0.035% with peaks at 451 and 615 nm, corresponding to the emissions of CsBr and CsxSnBrx+2, respectively. This work provided a new way to obtain stable Sn-based perovskite NCs and exhibited their potential for application in white light-emitting diodes (LEDs)

Superstable Cs<i>_x</i>SnBr_<i>x</i>+2@CsBr Nanocrystals with Over 1200 h of Half-Value PLQY in Air

Tin-based perovskites comprise one of the preferred nontoxic alternatives to Pb-based perovskites due to their desirable optoelectronic properties. However, there remains a crucial stability problem due to the property of Sn2+ oxidation. In this study, we reported stable tin-based perovskite nanocrystals (NCs) using stannous acetate as the Sn2+ source because of its stronger Sn–O bonding. To prevent the oxidation of Sn2+, a thin layer of CsBr coverage was formed in situ; tin-based perovskite NCs, CsxSnBrx+2@CsBr (1 x < 4), show a high photoluminescence quantum yield (PLQY) of 78.2% and high stability. The measured lifetime of PLQY decrease to half of the initial value is ∼1287 h under ambient conditions and ∼2200 h under a nitrogen atmosphere, respectively. Furthermore, the as-fabricated light-emitting diodes based on CsxSnBrx+2@CsBr NCs as the emitting layer exhibit a maximum luminescence of 16 cd/m2 and an external quantum efficiency of 0.035% with peaks at 451 and 615 nm, corresponding to the emissions of CsBr and CsxSnBrx+2, respectively. This work provided a new way to obtain stable Sn-based perovskite NCs and exhibited their potential for application in white light-emitting diodes (LEDs)

Additional file 1 of Fine mapping of TFL, a major gene regulating fruit length in snake gourd (Trichosanthes anguina L)

Supplementary Material

Superstable Cs<i>_x</i>SnBr_<i>x</i>+2@CsBr Nanocrystals with Over 1200 h of Half-Value PLQY in Air

Tin-based perovskites comprise one of the preferred nontoxic alternatives to Pb-based perovskites due to their desirable optoelectronic properties. However, there remains a crucial stability problem due to the property of Sn2+ oxidation. In this study, we reported stable tin-based perovskite nanocrystals (NCs) using stannous acetate as the Sn2+ source because of its stronger Sn–O bonding. To prevent the oxidation of Sn2+, a thin layer of CsBr coverage was formed in situ; tin-based perovskite NCs, CsxSnBrx+2@CsBr (1 x < 4), show a high photoluminescence quantum yield (PLQY) of 78.2% and high stability. The measured lifetime of PLQY decrease to half of the initial value is ∼1287 h under ambient conditions and ∼2200 h under a nitrogen atmosphere, respectively. Furthermore, the as-fabricated light-emitting diodes based on CsxSnBrx+2@CsBr NCs as the emitting layer exhibit a maximum luminescence of 16 cd/m2 and an external quantum efficiency of 0.035% with peaks at 451 and 615 nm, corresponding to the emissions of CsBr and CsxSnBrx+2, respectively. This work provided a new way to obtain stable Sn-based perovskite NCs and exhibited their potential for application in white light-emitting diodes (LEDs)

Table_1_Forward genetic studies reveal LsAPRR2 as a key gene in regulating the green color of pericarp in bottle gourd (Lagenaria siceraria).docx

The fruit peel color is an important factor that affects its quality. However, genes involved in regulating pericarp color in bottle gourd (Lagenaria siceraria) have not been explored to date. Genetic analysis of color traits in bottle gourd peel through a genetic population of six generations demonstrated that the green color of peels is inherited as a single gene dominant trait. Combined phenotype-genotype analysis of recombinant plants using BSA-seq mapped the candidate gene to a 22.645 Kb interval at the head end of chromosome 1. We observed that the final interval contained only one gene, LsAPRR2 (HG_GLEAN_10010973). Sequence and spatiotemporal expression analyses of LsAPRR2 unraveled two nonsynonymous mutations (A→G) and (G→C) in the parental CDS sequences. Further, LsAPRR2 expression was higher in all green-skinned bottle gourds (H16) at various stages of fruit development than in white-skinned bottle gourds (H06). Cloning and sequence comparison of the two parental LsAPRR2 promoter regions indicated 11 bases insertion and 8 SNPs mutations in the region -991~-1033, upstream of the start codon in white bottle gourd. Proof of GUS reporting system, Genetic variation in this fragment significantly reduced the expression of LsAPRR2 in the pericarp of white bottle gourd. In addition, we developed a tightly linked (accuracy 93.88%) InDel marker for the promoter variant segment. Overall, the current study provides a theoretical basis for comprehensive elucidation of the regulatory mechanisms underlying the determination of bottle gourd pericarp color. This would further help in the directed molecular design breeding of bottle gourd pericarp.</p