Anion-Doped Thickness-Insensitive Electron Transport Layer for Efficient Organic Solar Cells.

In organic solar cells, interfacial materials play essential roles in charge extraction, transportation, and collection. Currently, highly efficient and thickness-insensitive interfacial materials are urgently needed in printable large area module devices. Herein, water/alcohol-soluble conjugated polyelectrolyte PFNBT-Br, with medium bandgap based on benzothiadiazole, are doped by two alkali metal sodium salts, NaH2 PO2 , Na2 C2 O4 with different counter anions, to pursue high efficiency and thickness-insensitive electron-transport layers. Results show that the doping of electron-transport material can effectively promote the performance of the devices. Moreover, electron-transport layers doped by these salts with different counter anions show different behaviors in performances. Among which, the salt with oxalate anion C2 O4 2- (also named Ox2- ) shows much better device performance than the salt with hypophosphite anion (H2 PO2 - ), especially under the thick film condition (e.g., 50 nm). The greatly enhanced performances of interfacial material doped by Ox2- are due to reduced series resistance between the active layer material and the electrode, reduced dark-current, improved charge transport, and extraction efficiency, and decreased charge recombination for the devices at thick-film condition. These results demonstrated that n-doping could be a great potential strategy for making thickness-insensitive interfacial layers, besides, the performances can be further improved by carefully selecting salts.

dbPTM in 2022: an updated database for exploring regulatory networks and functional associations of protein post-translational modifications.

Protein post-translational modifications (PTMs) play an important role in different cellular processes. In view of the importance of PTMs in cellular functions and the massive data accumulated by the rapid development of mass spectrometry (MS)-based proteomics, this paper presents an update of dbPTM with over 2 777 000 PTM substrate sites obtained from existing databases and manual curation of literature, of which more than 2 235 000 entries are experimentally verified. This update has manually curated over 42 new modification types that were not included in the previous version. Due to the increasing number of studies on the mechanism of PTMs in the past few years, a great deal of upstream regulatory proteins of PTM substrate sites have been revealed. The updated dbPTM thus collates regulatory information from databases and literature, and merges them into a protein-protein interaction network. To enhance the understanding of the association between PTMs and molecular functions/cellular processes, the functional annotations of PTMs are curated and integrated into the database. In addition, the existing PTM-related resources, including annotation databases and prediction tools are also renewed. Overall, in this update, we would like to provide users with the most abundant data and comprehensive annotations on PTMs of proteins. The updated dbPTM is now freely accessible at https://awi.cuhk.edu.cn/dbPTM/.

dbAMP 2.0: updated resource for antimicrobial peptides with an enhanced scanning method for genomic and proteomic data.

The last 18 months, or more, have seen a profound shift in our global experience, with many of us navigating a once-in-100-year pandemic. To date, COVID-19 remains a life-threatening pandemic with little to no targeted therapeutic recourse. The discovery of novel antiviral agents, such as vaccines and drugs, can provide therapeutic solutions to save human beings from severe infections; however, there is no specifically effective antiviral treatment confirmed for now. Thus, great attention has been paid to the use of natural or artificial antimicrobial peptides (AMPs) as these compounds are widely regarded as promising solutions for the treatment of harmful microorganisms. Given the biological significance of AMPs, it was obvious that there was a significant need for a single platform for identifying and engaging with AMP data. This led to the creation of the dbAMP platform that provides comprehensive information about AMPs and facilitates their investigation and analysis. To date, the dbAMP has accumulated 26 447 AMPs and 2262 antimicrobial proteins from 3044 organisms using both database integration and manual curation of >4579 articles. In addition, dbAMP facilitates the evaluation of AMP structures using I-TASSER for automated protein structure prediction and structure-based functional annotation, providing predictive structure information for clinical drug development. Next-generation sequencing (NGS) and third-generation sequencing have been applied to generate large-scale sequencing reads from various environments, enabling greatly improved analysis of genome structure. In this update, we launch an efficient online tool that can effectively identify AMPs from genome/metagenome and proteome data of all species in a short period. In conclusion, these improvements promote the dbAMP as one of the most abundant and comprehensively annotated resources for AMPs. The updated dbAMP is now freely accessible at http://awi.cuhk.edu.cn/dbAMP.

Dodecacyclic-Fused Electron Acceptors with Multiple Electron-Deficient Units for Efficient Organic Solar Cells.

Fused aromatic cores in non-fullerene electron acceptors (NFEAs) play a significant role in determining their optoelectronic properties and photovoltaic performance. In this work, a dodecacyclic-fused core with three electron-deficient units is synthesized through a double intramolecular Cadogan reduction cyclization. Terminal groups with different halogen substitution (F or Cl) are grafted onto the dodecacyclic-fused core to afford MS-4F and MS-4Cl, both of which showed strong and broad absorption, narrow bandgaps around 1.40 eV, and variable molecular packing model in pristine and blend films. Photovoltaic performance of solar cells containing MS-4F and MS-4Cl as NFEAs were investigated with resultant power conversion efficiencies (PCEs) of 11.75 % and 11.79 %, respectively. The mechanism study indicates that both of PBDB-T : MS-4F- and PBDB-T : MS-4Cl-based devices displayed high hole and electron mobility values, efficient charge transfer, and low charge recombination etc. These results indicate that designing multiple-fused aromatic cores with multiple electron-deficient units is a promising strategy to obtain high-performance NFEAs.

Microemulsion-Assisted Self-Assembly and Synthesis of Size-Controlled Porphyrin Nanocrystals with Enhanced Photocatalytic Hydrogen Evolution.

Design and engineering of highly efficient light-harvesting nanomaterial systems to emulate natural photosynthesis for maximizing energy conversion have stimulated extensive efforts. Here we present a new class of photoactive semiconductor nanocrystals that exhibit high-efficiency energy transfer for enhanced photocatalytic hydrogen production under visible light. These nanocrystals are formed through noncovalent self-assembly of In(III) meso-tetraphenylporphine chloride (InTPP) during microemulsion assisted nucleation and growth process. Through kinetic control, a series of uniform nanorods with controlled aspect ratio and high crystallinity have been fabricated. Self-assembly of InTPP porphyrins results in extensive optical coupling and broader coverage of the visible spectrum for efficient light harvesting. As a result, these nanocrystals display excellent photocatalytic hydrogen production and photostability under the visible light in comparison with the commercial InTPP porphyrin powders.