Solid Additive-Assisted Layer-by-Layer Processing for 19%Efficiency Binary Organic Solar Cells

Morphology is of great significance to the performance of organic solar cells(OSCs),since appropriate morphology could not only promote the exciton dissociation,but also reduce the charge recombination.In this work,we have developed a solid additive-assisted layer-by-layer(SAA-LBL)processing to fabricate high-efficiency OSCs.By adding the solid additive of fatty acid(FA)into polymer donor PM6 solution,controllable pre-phase separation forms between PM6 and FA.This intermixed morphology facilitates the diffusion of acceptor Y6 into the donor PM6 during the LBL processing,due to the good miscibility and fast-solvation of the FA with chloroform solution dripping.Interestingly,this results in the desired morphology with refined phase-separated domain and vertical phase-separation structure to better balance the charge transport/collection and exciton dissociation.Consequently,the binary single junction OSCs based on PM6:Y6 blend reach champion power conversion efficiency(PCE)of 18.16%with SAA-LBL processing,which can be generally applicable to diverse systems,e.g.,the PM6:L8-BO-based devices and thick-film devices.The efficacy of SAA-LBL is confirmed in binary OSCs based on PM6:L8-BO,where record PCEs of 19.02%and 16.44%are realized for devices with 100 and 250 nm active layers,respectively.The work provides a simple but effective way to control the morphology for high-efficiency OSCs and demonstrates the SAA-LBL processing a promising methodology for boosting the industrial manufacturing of OSCs.

Non-fused medium bandgap electron acceptors for efficient organic photovoltaics

The cost-effective organic semiconductors are strongly needed in organic photovoltaics(OPVs). Herein,two medium bandgap(MBG) electron acceptors, TPT4F and TPT4Cl are developed via the new design of multi-noncovalent interaction assisted unfused core, flanked with two electron withdrawing end groups. These fullly non-fused MBG acceptors adapt the planar and rigid conformation in solid, therefore exhibiting the ordered face-on stacking and strong photoluminescence in films. As results, TPT4Cl^(-)based OPVs, upon blending with the PBDB-TF polymer donor, have achieved a power conversion efficiency of 10.16% with a low non-radiative loss of 0.27 e V, representing one of the best fullly non-fused medium bandgap acceptors with desirable cost-efficiency balance.

Potential application of proteolysis targeting chimera(PROTAC)modification technology in natural products for their targeted protein degradation

There are numerous evaluations of natural products,of which majority are food bioactives,performed up to date for their various health beneficial activities via targeting specific proteins.However,the direct identification of a targeted protein remains unexplored for natural occurring compounds.Proteolysis targeting chimera(PROTAC)is a type of bifunctional chimeric molecules that can directly degrade the binding proteins targeted by bioactive molecules in an ubiquitin-proteasome pathway.As the agents in protein degradation dependent on ubiquitin ligase,the bifunctional molecule connects the target protein ligand and E3 ligase ligand together via an appropriate linker.It is highly selective and efficient to induce the ubiquitin-mediated degradation of targeted binding proteins.Therefore,it has been demonstrated that the PROTAC technology has broad application in the modulation of the target protein level.In this review,we outlined the advances in PROTAC combined molecule compounds,summarized its quantitative structure-activity relationship,and finally reviewed the methods applied in identifying the target proteins of natural products.We hope it will provide an insightful application of PROTAC techniques in the target protein identification of natural products including food bioactive molecules.

Random Terpolymer Based on Simple Siloxane-functionalized Thiophene Unit Enabling High-performance Non-fullerene Organic Solar Cells

Incorporation of siloxane-functionalized units into polymers backbone has proven to be an efficient strategy to improve photovoltaic performance. In this work, a low-cost siloxane-containing unit was developed to construct a series of terpolymers, and the effects of siloxane on the polymer performance were systematically studied. Different contents of thiophene containing siloxane-functionalized side chain were introduced into PM6 to obtain a series of polymers(PM6, PM6-SiO-10, PM6-SiO-20 and PM6-SiO-30). The siloxane-functionalized side chains in polymers have only a slight effect on the absorption behavior and frontier molecular orbitals. However, when the siloxane content increased, the terpolymers' aggregation property decreased and the temperature-dependency increased, leading to improved donor-acceptor compatibility. The power conversion efficiency(PCE) based on PM6:Y6, PM6-SiO-20:Y6 and PM6-SiO-30:Y6 devices was 15.64%, 16.03% and 15.82%, respectively. In comparison, the active layer based on PM6-SiO-10:Y6 exhibits the most appropriate phase separation morphology, resulting in effective exciton dissociation, more balanced hole-electron transport and less recombination. Consequently, the highest PCE of 16.69% with an outstanding shortcircuit current density of 26.96 mA·cm^(-2) was obtained, which are one of the highest values for siloxane-functionalized polymer-based devices.This work demonstrates that finely controlling the content of siloxane-functionalized thiophene is beneficial for obtaining high-performance terpolymer donors and provides a novel and low-cost method to improve photovoltaic performance.

Carbazolebis(thiadiazole)-core based non-fused ring electron acceptors for efficient organic solar cells

Non-fused ring electron acceptors(NFREAs)have a broad application prospect in the commercialization of organic solar cells(OSCs)due to the advantages of simple synthesis and low cost.The selection of intermediate block cores of non-fused frameworks and the establishment of the relationship between molecular structure and device performance are crucial for the realization of high-performance OSCs.Herein,two A-D-A’-D-A type NFREAs namely CBTBO-4F and CBTBO-4Cl,constructed with a novel electron-deficient block unit N-(2-butyloctyl)-carbazole[3,4-c:5,6-c]bis[1,2,5]thiadiazole(CBT)and bridging unit 4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b’]dithiophene(DTC)coupling with different terminals(IC-2F/2Cl),were designed and synthesized.The two NFREAs feature broad and strong photoresponse from 500 nm to 900 nm due to the strong intramolecular charge transfer characteristics.Compared with CBTBO-4F,CBTBO-4Cl shows better molecular planarity,stronger crystallinity,more ordered molecular stacking,larger van der Waals surface,lower energy level and better active layer morphology,contributing to much better charge separation and transport behaviors in its based devices.As a result,the CBTBO-4Cl based device obtains a higher power conversion efficiency of 10.18%with an open-circuit voltage of 0.80 V and a short-circuit current density of 21.20 mA/cm^(2).These results not only demonstrate the great potential of CBT,a new building block of the benzothiazole family,in the construction of high-performance organic conjugated semiconductors,but also suggest that the terminal chlorination is an effective strategy to improve device performance.

π-Extended End Groups Enable High-Performance All-Polymer Solar Cells with Near-Infrared Absorption

Narrow-bandgap n-type polymers are essential for advancing the development of all-polymer solar cells(all-PSCs).Herein,we developed a novel polymer acceptor PNT withπ-extended 2-(3-oxo-2,3-dihydro-1H-cyclopenta[b]naphthalen-1-ylidene)malononitrile(CPNM)end groups.Compared to commonly used 2-(3-oxo-2,3-dihydro-1H-cyclopenta[b]naphthalen-1ylidene)malononitrile(IC)units,CPNM units have a further extended fused ring,providing the PNT polymer with extended absorption into the near-IR region(903 nm)and exhibiting a narrow optical bandgap(1.37 eV).Furthermore,PNT exhibits a high electron mobility(6.79×10^(−4) cm^(2)·V^(−1)·S^(−1))and a relatively high-lying lowest unoccupied molecular orbital(LUMO)energy level of−3.80 eV.When blended with PBDB-T,all-PSC achieves a power conversion efficiency(PCE)of 13.7%and a high short-circuit current density(JSC)of 24.4 mA·cm^(−2),mainly attributed to broad absorption(600—900 nm)and efficient charge separation and collection.Our study provides a promising polymer acceptor for all-PSCs and demonstrates thatπ-extended CPNM units are important to achieve high-performance for all-PSCs.

Alkyl side chain engineering enables high performance as-cast organic solar cells of over 17%efficiency

Achieving high-performance as-cast OSCs is crucial for industrialization in the future,owing to the advantages of better stability,environmental-friendly,and decreasing production cost.In this regard,we synthesized an ADA′D-A type acceptor,Y6-eC6-BO,by shortening the straight alkyl side-chains on the thiophene position from C_(11) to C_(6) as well as lengthening the branched alkyl side-chains on the pyrrole position of Y6 to achieve a stronger crystallization and better miscibility than Y6.As a result,the corresponding chloroform-processed as-cast PM6:Y6-eC6-BO OSC showed a high PCE of 17.33%,which was one of the highest efficiencies of as-cast OSCs.And the as-cast PM6:Y6-eC6-BO OSCs processed from o-xylene displayed a PCE of 16.38%,as far as we know,this is among the highest efficiencies of non-halogenated-solvent processed as-cast OSCs.These results demonstrated tailoring the alkyl side-chain of NFAs is a feasible and simple approach to achieve high performance as-cast OSCs and provides guideline in molecular design in the future.

NaCl胁迫下哈茨木霉ACCC32524的转录组和代谢组分析

【目的】通过分析NaCl胁迫下哈茨木霉(Trichoderma harzianum)ACCC32524转录组和代谢组数据,研究差异表达基因及次级代谢产物的变化情况,初步探索响应NaCl胁迫的分子机制。【方法】利用Illumina HiSeq XTen高通量测序平台完成0、0.4、0.6 mol/L NaCl浓度胁迫培养下哈茨木霉ACCC32524的转录组测序,GC-TOF-MS技术完成对0mol/L和0.6mol/LNaCl胁迫培养下的差异次级代谢产物检测,利用相关软件及数据库对差异表达基因(DEGs)和次级代谢产物的注释、筛选和分类,并进行RT-qPCR验证。【结果】本研究分别得到0.4 mol/L和0.6 mol/L NaCl胁迫下417和733条差异表达基因;GO富集分析显示,分别有318和582条差异表达基因注释到生物学过程、分子功能和细胞组分3个一级分类和40个二级分类;COG分类结果表明分别有232和414条转录本为20个类别,涉及差异表达基因最多的分别为氨基酸的转运和代谢、一般功能预测、碳水化合物的转运和代谢;KEGG代谢途径分析结果表明,分别有75和96条基因归到25个代谢通路中(P≤0.05),其中涉及差异基因最多的是氨基酸的生物合成和2-氧代羧酸代谢通路。从转录组数据中共筛选出与渗透调节、离子转运、活性氧清除等22个耐盐相关基因。0 mol/L和0.6 mol/L NaCl胁迫下的代谢组数据中共筛选出101个差异次级代谢产物,包括8种积累量上调和93种下调物质,其中36个得到定性,分属于糖类、有机酸和氨基酸等9个分类中。RT-qPCR验证挑选的差异表达基因的表达量变化,均与RNA-seq分析结果一致。【结论】NaCl胁迫下引起哈茨木霉ACCC32524基因及次级代谢产物发生明显变化,细胞代谢途径发生明显偏移,这些进程共同作用减少NaCl对细胞的毒害作用,为木霉菌的耐盐机理研究提供重要信息。

Identification and Validation of an Immune-related Prognostic Signature for Hepatocellular Carcinoma

Background and Aims:The immune system plays vital roles in hepatocellular carcinoma(HCC)initiation and progression.The present study aimed to construct an immune-gene related prognostic signature(IRPS)for predicting the prognosis of HCC patients.Methods:Gene expression data were retrieved from The Cancer Genome Atlas database.The IRPS was established via least absolute shrinkage and selection operator(LASSO)and multivariate Cox regression analysis.The prognostic values of the IRPS were further validated using the International Cancer Genome Consortium(ICGC)dataset.Results:A total of 62 genes were identified as candidate immune-related prognostic genes.According to the results of Lasso and multivariate Cox regression analysis,we established an IRPS and confirmed its stability and reliability in the ICGC dataset.The IRPS was significantly associated with advanced clinicopathological characteristics.Both Cox regression analyses revealed that the IRPS could be independent risk factors influencing prognosis of HCC patients.The relationships between the IRPS and infiltration of immune cells demonstrated that the IRPS was associated with immune cell infiltration.Furthermore,a nomogram was constructed to estimate the survival probability of HCC patients.Conclusions:The IRPS was effective for predicting prognosis of HCC patients,which might serve as novel prognostic and therapeutic biomarkers for HCC.

Over 18% binary organic solar cells enabled by isomerization of non-fullerene acceptors with alkylthiophene side chains

Side-chain engineering has been demonstrated as an effective method for fine-tuning the optical,electrical,and morphological properties of organic semiconductors toward efficient organic solar cells(OSCs).In this work,three isomeric non-fullerene small molecule acceptors(SMAs),named as BTP-4F-T2C8,BTP-4F-T2EH and BTP-4F-T3EH,with linear and branched alkyl chains substituted on the α or β positions of thiophene as the side chains,were synthesized and systematically investigated.The results demonstrate that the size and substitution position of alkyl side chains can greatly affect the electronic properties,molecular packing as well as crystallinity of the SMAs.After blending with donor polymer D18-Cl,the prominent device performance of 18.25% was achieved by the BTP-4F-T3EH-based solar cells,which is higher than those of the BTP-4F-T2EH-based(17.41%)and BTP-4F-T2C8-based(15.92%)ones.The enhanced performance of the BTP-4F-T3EH-based devices is attributed to its stronger crystallinity,higher electron mobility,suppressed bimolecular recombination,and the appropriate intermolecular interaction with the donor polymer.This work reveals that the side chain isomerization strategy can be a practical way in tuning the molecular packing and blend morphology for improving the performance of organic solar cells.