Silane Doping for Efficient Flexible Perovskite Solar Cells with Improved Defect Passivation and Device Stability

In this work, doping 3-amino-propyl triethoxysilane (APTES) into a perovskite precursor is proven to be an effective strategy, which can passivate crystal defects, control the crystallization rate, and improve the morphology. APTES can form oligomers through hydrolysis and a condensation reaction, thus blocking the invasion of external water molecules. In addition, the lone pair electrons on the N atom in the amino group of APTES form a coordination bond with perovskite by sharing the empty 6p orbital on Pb2+, which can effectively passivate the defects of the film and realize a highly uniform and dense perovskite film with preferential crystal growth orientation. The film exhibits high (110) crystal plane orientation and long carrier lifetime and mobility, which improves the performance of flexible perovskite solar cells. Using this approach, the champion device presents an optimal power conversion efficiency of 19.84% with much promoted air stability. Moreover, the efficiency of flexible devices does not decrease after maximum power point irradiation for 360 s

Universal Low-Temperature Process for Preparation of Multifunctional High-Performance Antireflective Mesoporous Silica Coatings on Transparent Polymeric Substrates

In this work, we developed a universal low-temperature process for the preparation of multifunctional and robust mesoporous silica antireflective coatings on transparent polymeric substrates. The mesoporous silica layer was formed after UV–O₃ exposure and ammonia vapor treatment of dried poly­(ethylene glycol)-<i>block</i>-poly­(propylene glycol)-<i>block</i>-poly­(ethylene glycol) (F127)-containing acidic silica gel. The optical and antiscrubbing properties of the mesoporous silica coating were comparable to those of the coating prepared at 250 °C. The highest optical transmittance reached 99.55%, and the transmittance loss was only 1.02% after 400 scrubbing cycles. The coating surface formed by the low-temperature process was hydrophilic, resulting in excellent antifogging properties. The low-temperature process was successfully applied on various transparent polymeric substrates including polyimide, polyethylene terephthalate, polyethylene naphthalate, and polycarbonate. The excellent optical and mechanical performances of the mesoporous silica antireflective coatings on transparent polymeric substrates allow a wide range of practical applications, especially in the field of flexible electronics

Silver Nanowire-Based Flexible Transparent Composite Film for Curvature Measurements

A transparent, flexible, and conductive epoxy resin film embedded with silver nanowires is fabricated through a simple process. The effect of silver nanowire areal mass density on the electrical and optical properties of films is investigated. It is found that resistance of the transparent composite film will change regularly during the bending process. The influence mechanism of bending behavior on the electrical property is explored. On the basis of this mechanism, the curvature in the bending process can be acquired immediately by measuring the resistance of the composite film. The high elastic modulus (800 MPa) of the composite film is a benefit for distinguishing the factor of resistance change caused by bending or stretching with low force. Additionally, high stability of the bending detector is demonstrated with 500 repeated bending cycles and a 6-month durability test

Multifunctional Antireflection Coatings Based on Novel Hollow Silica–Silica Nanocomposites

Antireflection (AR) coatings that exhibit multifunctional characteristics, including high transparency, robust resistance to moisture, high hardness, and antifogging properties, were developed based on hollow silica–silica nanocomposites. These novel nanocomposite coatings with a closed-pore structure, consisting of hollow silica nanospheres (HSNs) infiltrated with an acid-catalyzed silica sol (ACSS), were fabricated using a low-cost sol–gel dip-coating method. The refractive index of the nanocomposite coatings was tailored by controlling the amount of ACSS infiltrated into the HSNs during synthesis. Photovoltaic transmittance (<i>T</i>_PV) values of 96.86–97.34% were obtained over a broad range of wavelengths, from 300 to 1200 nm; these values were close to the theoretical limit for a lossy single-layered AR coating (97.72%). The nanocomposite coatings displayed a stable <i>T</i>_PV, with degradation values of less than 4% and 0.1% after highly accelerated temperature and humidity stress tests, and abrasion tests, respectively. In addition, the nanocomposite coatings had a hardness of approximately 1.6 GPa, while the porous silica coatings with an open-pore structure showed more severe degradation and had a lower hardness. The void fraction and surface roughness of the nanocomposite coatings could be controlled, which gave rise to near-superhydrophilic and antifogging characteristics. The promising results obtained in this study suggest that the nanocomposite coatings have the potential to be of benefit for the design, fabrication, and development of multifunctional AR coatings with both omnidirectional broadband transmission and long-term durability that are required for demanding outdoor applications in energy harvesting and optical instrumentation in extreme climates or humid conditions

Phylogenetic relationships among STB03, BTS02, and 30 <i>Echinochloa</i> accessions based on the nucleotide sequences of <i>trn</i>T-L-F region of the chloroplast genome.

<p>See the study by Yamaguchi <i>et al.</i> (2005) for code numbers of the 30 accessions <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0113657#pone.0113657-Aoki1" target="_blank">[12]</a>. The tree was constructed using NJ method. Bootstrap values with less than 50 are not shown.</p

Divergence time of the genus <i>Echinochloa</i>.

<p>Divergence time was estimated using BEAST based on the complete chloroplast genomes of six species (<i>E. oryzicola</i>, <i>E. crus-galli</i>, <i>P. virgatum</i>, <i>S. bicolor</i>, <i>Z. mays</i>, and <i>O. sativa</i>). The numbers showed at nodes indicate divergence time.</p

Visualization of alignments of chloroplast genome sequences.

<p>The sequence identity was plotted with the <i>E.oryzicola</i> chloroplast genome as the reference. Sequence identity with 50%–100% is shown. Exonic regions and conserved non-coding sequences (CNS) are colored in blue and red, respectively.</p

<i>Echinochloa</i> Chloroplast Genomes: Insights into the Evolution and Taxonomic Identification of Two Weedy Species

<div><p>The genus <i>Echinochloa</i> (Poaceae) includes numerous problematic weeds that cause the reduction of crop yield worldwide. To date, DNA sequence information is still limited in the genus <i>Echinochloa</i>. In this study, we completed the entire chloroplast genomes of two <i>Echinochloa</i> species (<i>Echinochloa oryzicola</i> and <i>Echinochloa crus-galli</i>) based on high-throughput sequencing data from their fresh green leaves. The two <i>Echinochloa</i> chloroplast genomes are 139,891 and 139,800 base pairs in length, respectively, and contain 131 protein-coding genes, 79 indels and 466 substitutions helpful for discrimination of the two species. The divergence between the genus <i>Echinochloa</i> and <i>Panicum</i> occurred about 21.6 million years ago, whereas the divergence between <i>E. oryzicola</i> and <i>E. crus-galli</i> chloroplast genes occurred about 3.3 million years ago. The two reported <i>Echinochloa</i> chloroplast genome sequences contribute to better understanding of the diversification of this genus.</p></div