Water/alcohol soluble cathode interfacial materials (CIMs) are playing important roles in optoelectronic devices such as organic light emitting diodes, perovskite solar cells and organic solar cells (OSCs). Herein, n-doped solution-processable single-wall carbon nanotubes (SWCNTs)-containing CIMs for OSCs are developed by dispersing SWCNTs to the typical CIMs perylene diimide (PDI) derivatives PDIN and PDINO. The Raman and X-ray photoelectron spectroscopy (XPS) measurement results illustrate the n-doped behavior of SWCNTs by PDIN/PDINO in the blend CIMs. The blended and n-doped SWCNTs can tune the work function and enhance the conductivity of the PDI-derivative/SWCNT (PDI-CNT) composite CIMs, and the composite CIMs can regulate and down-shift the work function of cathode, reduce the charge recombination, improve the charge extraction rate and enhance photovoltaic performance of the OSCs. High power conversion efficiency (PCE) of 17.1% and 17.7% are obtained for the OSCs based on PM6:Y6 and ternary PM6:Y6:PC71BM respectively with the PDI-CNT composites CIMs. These results indicate that the n-doped SWCNT-containing composites, like other n-doped nanomaterials such as zero dimensional fullerenes and two dimensional graphenes, are excellent CIMs for OSCs and could find potential applications in other optoelectronic devices.
Indacenodithiophene(IDT) derivatives are kinds of the most representative and widely used cores of small molecule acceptors(SMAs) in organic solar cells(OSCs).Here we systematically investigate the influence of end-group fluo rination density and position on the photovoltaic properties of the IDT-based SMAs IDIC-nF(n=0,2,4).The absorption edge of IDIC-nF red-shifts with the π-π stacking and crystallinity improvement,and their electronic energy levels downshift with increasing n.Due to the advantages of J sc and FF as well as acceptable V oc ,the difluorinated IDIC-2 F acceptor based OSCs achieve the highest power conversion efficiency(PCE) of 13%,better than the OSC devices based on IDIC and IDIC-4 F as acceptors.And the photovoltaic performance of the PTQ10:IDIC-2 F OSCs is insensitive to the active layer thickness:PCE still keep high values of 12.00% and 11.46% for the devices with active layer thickness of 80 and 354 nm,respectively.This work verifies that fine and delicate modulation of the SMAs molecular structure could optimize photovoltaic performance of the corresponding OSCs.Meanwhile,the thickness-insensitivity property of the OSCs has potential for large-scale and printable fabrication technology.
Graphene dispersions in low-boiling-point green solvents have wide applications in coatings, conducting inks, batteries, electronics and solar cells. Two three-dimensional (3D) cathode interfacial materials (CIMs) (1,3,5,7,9,11,13,15-octa-(9-bis(30-( N,N -dimethylamino)propyl)-2,7-fluorene)-vinylpentacyclo-octasiloxane) (POSSFN) and (1,3,5,7-tetra-(9-bis(30-( N,N -dimethylamino)propyl)-2,7-fluorene)-adamantane) (ADMAFN) are excellent surfactants for dispersing graphene in ethanol at the concentration of 0.97–1.18 mg mL −1 , in agreement with their calculated large adsorption energies on graphene. The results of electron spin resonance, Raman, scanning Kelvin probe microscopy and X-ray photoelectron spectroscopy measurements indicate that the amino groups could n-dope graphene or form dipole interaction with graphene. The two 3D-surfactant-based graphene composites (POSSFN-G and ADMAFN-G) can work as high-performance CIMs in organic solar cells (OSCs), which improve the power conversion efficiency (PCE) of the OSCs based on PM6:Y6 to 15.9%–16.1%. ADMAFN forms dipole interaction with graphene in ADMAFN-G and the composite CIM delivers high PCE of 16.11% in the OSCs, while POSSFN forms n-doped composition with graphene in POSSFN-G which works well as thicker CIM film in the OSCs.
Three alcohol-soluble nonconjugated polymers poly [p-(N,N-dimethylamino)styrene] (PSN), poly[p-(N,N-dimethylamino)styrene] oxide (PSO), and poly[p-(N,N-dimethylamino)styrene] mesylate (PSM) were devised and synthesized for the application as cathode interlayers in the organic solar cells (OSCs) based on PBDB-T:IT-M. All of the polymers contain a highly polarized amino or ammonium group at the side chains, which can improve electron collection ability of the cathode interfacial layer of the OSCs. Both the amino and ammonium group with a negative ion of oxygen allow PSN and PSO to possess intermolecular n-doping effect with the IT-M acceptor at the interface. The understanding of the relationship between the n-doping effect and the cathode interlayer structures may offer additional insights to further develop novel cathode interfacial materials for OSCs.
Solution-processable n-doped graphene-containing cathode interfacial material with a low work function demonstrates 16.52% power conversion efficiency in organic solar cells.
An alcohol soluble hybrid organic–inorganic three-dimensional material POSS-FN has been synthesized and assessed as a cathode interlayer within organic solar cells consisting of a PBDT-BT:PC61BM bulk heterojunction.
The development of a high-performance polymer PBDT-BT for bulk heterojunction solar cell devices is summarized. The polymer was first synthesized by Stille polycondensation, and solar cell devices in conventional geometry were optimized through the use of a lithium salt cathode interlayer reaching 6% power conversion efficiency. Improvements were made to the synthesis of the polymer using Suzuki polycondensation giving high-molecular weight material in the M-n = 100 kg/mol range. Further device optimization in inverted geometry gave power conversion efficiency of over 9%. The synthesis scalability as well as the batch-to-batch reproducibility of the polymer were extensively investigated.
A high molecular weight donor-acceptor conjugated polymer is synthesized using the Suzuki polycondensation method. Using this polymer, a single-junction bulk-heterojunction solar cell is fabricated giving a power conversion efficiency of 9.4% using a fullerene-modified ZnO interlayer at the cathode contact.
We present a strategy to fabricate polymer solar cells in inverted geometry by self-organization of alcohol soluble cathode interfacial materials in donor-acceptor bulk heterojunction blends. An amine-based fullerene [6,6]-phenyl-C61-butyric acid 2-((2-(dimethylamino)-ethyl)(methyl)amino)ethyl ester (PCBDAN) is used as an additive in poly(3-hexylthiophene) (P3HT) and 6,6-phenyl C61-butyric acid methyl ester (PCBM) blend to give a power conversion efficiency of 3.7% based on devices ITO/P3HT:PCBM:PCBDAN/MoO3/Ag where the ITO alone is used as the cathode. A vertical phase separation in favor of the inverted device architecture is formed: PCBDAN is rich on buried ITO surface reducing its work function, while P3HT is rich on air interface with the hole-collecting electrode. The driving force of the vertical phase separation is ascribed to the surface energy and its components of the blend compositions and the substrates. Similar results are also found with another typical alcohol soluble cathode interfacial materials, poly[(9,9-bis(3'-(N, N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN), implying that self-organization may be a general phenomenon in ternary blends. This self-organization procedure could eliminate the fabrication of printing thin film of interlayers or printing on such thin interlayers and would have potential application for roll-to-roll processing of polymer solar cells.
An amine-based, alcohol-soluble fullerene [6,6]phenyl-C-61-butyric acid 2-((2-(dimethylamino)ethyl)(methyl)amino)-ethyl ester (PCBDAN) with 4-fold electron mobility of 6,6-phenyl-C-61-butyric acid methyl ester (PCBM) is applied successfully as an acceptor and cathode interfacial material in polymer solar cells ITO/P3HT:PCBDAN/MoO3/Ag, where indium tin oxide (ITO) alone is used as the cathode and poly(3-hexylthiophene) (P3HT) is used as a donor. The X-ray photoelectron spectroscopy (XPS) depth profile confirming a favorable vertical phase separation is formed where P3HT is rich at the air/active blend interface and PCBDAN is rich at the buried interface with ITO and, thus, reduces the work function of ITO for use as the cathode. A moderate power conversion efficiency (PCE) of 3.1% is achieved. The slightly low PCE could be due to unoptimized morphology and low structure ordering of P3HT in the blends. However, this result demonstrates that the amine-based fullerene could be used as the acceptor and cathode interfacial material, which eliminated the multilayer device fabrication process. Because PCBDAN has high electron mobility, it would have potential applications in nano-structured organic solar cells. In the near future, alcohol-processable, high-efficient organic/polymer solar cells can be anticipated.
Among alcohol soluble self n-doped fullerene ammonium derivatives, the title fullerene showed the best solvent resistance and inverted polymer solar cells retained high efficiency at 82 nm of this interlayer.
Efficient low-band-gap polymers are one key component for constructing tandem solar cells with other higher-band-gap materials to harvest wide absorption of the solar spectrum. The N-acyldithieno[3,2-b:2',3'-d]pyrrole (DTP) building block is used for making low-band-gap polymers. It is attractive because of its strong donating ability and relatively low highest-occupied-molecular-orbital level in comparison with the N-alkyl DTP building block. However, additional solubilizing groups on the accepting units are needed for soluble donor-acceptor polymers based on the N-alkanoyl DTP building block. Combining N-benzoyl DTP with a 4,7-dithieno-2,1,3-benzothiadiazole building block, a polymer with a low band gap of 1.44 eV, delivers a high short-circuit current of 17.1 mA/cm(2) and a power conversion efficiency of 3.95%, which are the highest for the devices with DTP-containing materials. Herein, an alcohol-soluble diamine-modified fullerene cathode interfacial layer improved the device efficiency significantly more than the mono-amine analogue.
Two [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) derivatives with side-chain-attaching amine end groups, PCBDAN and PCBDANI, are synthesized. Both PCBDAN and PCBDANI show excellent photovoltaic performance as cathode buffer layers to replace Ca in polymer solar cells.
An alcohol-soluble hyperbranched conjugated polymer HBPFN with a dimethylamino moiety is synthesized and used as a cathode interlayer. A PCE of 7.7% is obtained for PBDTTT-C-T/PC71 BM based solar cells. No obvious interfacial dipole is found at the interface between the active layer and HBPFN however, an interfacial dipole with the cathode could be one of the reasons for the enhanced performance.
BACKGROUND:Pedigrees with multiple genotyped family members have been underutilised in breast cancer (BC) genetic-association studies. We developed a pedigree-based analytical framework to characterise single-nucleotide polymorphism (SNP) associations with BC risk using data from 736 BC families ascertained through multiple affected individuals. On average, eight family members had been genotyped for 24 SNPs previously associated with BC. METHODS:Breast cancer incidence was modelled on the basis of SNP effects and residual polygenic effects. Relative risk (RR) estimates were obtained by maximising the retrospective likelihood (RL) of observing the family genotypes conditional on all disease phenotypes. Models were extended to assess parent-of-origin effects (POEs). RESULTS:Thirteen SNPs were significantly associated with BC under the pedigree RL approach. This approach yielded estimates consistent with those from large population-based studies. Logistic regression models ignoring pedigree structure generally gave larger RRs and association P-values. SNP rs3817198 in LSP1, previously shown to exhibit POE, yielded maternal and paternal RR estimates that were similar to those previously reported (paternal RR=1.12 (95% confidence interval (CI): 0.99-1.27), P=0.081, one-sided P=0.04; maternal RR=0.94 (95% CI: 0.84-1.06), P=0.33). No other SNP exhibited POE. CONCLUSION:Our pedigree-based methods provide a valuable and efficient tool for characterising genetic associations with BC risk or other diseases and can complement population-based studies.
Charge extraction properties of various binary and ternary blends of organic photovoltaic devices covering both polymers and small molecules are studied. Due to their bipolar nature, both slow and fast carrier mobilities are identified from the extraction current transient. The equilibrium carrier concentration is also estimated for each of the blend films. The product of the slow carrier mobility and equilibrium concentration spreading two orders of magnitude can be used to estimate the short circuit current density. A good agreement between the estimated and measured short circuit current density is obtained with the accuracy reliant on the estimation of the slowest carrier mobility. This simplistic approach will be very useful to predict the short circuit current density for devices based on new materials.
Three dimensional conjugated polymers with pendant ionic ammoniums or polar amines and their linear analogues as cathode interfacial layers were used for organic photovoltaic cells based on blends of poly [(9,9-di-n-octyl-2,7-fluorene)-alt-(5,5-(4′,7′-di-2-thienyl)-2′,1′,3′-benzothiadiazole)] (PFOTBT) or poly(3-hexylthiophene) as the donor and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) as the acceptor. The alcohol soluble conjugated polymer interlayers can improve the device performance significantly by simultaneous enhancements of the open-circuit voltage, short-circuit current density, and fill factor. An increase of the power conversion efficiency from 2.62% to 4.67% by 78% was observed with poly[(2,7,2′,7′-spirobifluorene-co-(9,9-bis(6′-((N,N,N-trimethyl) ammonium) hexyl)-2,7-fluorene) dibromide)] based on PFOTBT-PC61BM blend.
This index covers all technical items - papers, correspondence, reviews, etc. - that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author's name. The primary entry includes the co-authors' names, the title of the paper or other item, and its location, specified by the publication abbreviation, year, month, and inclusive pagination. The Subject Index contains entries describing the item under all appropriate subject headings, plus the first author's name, the publication abbreviation, month, and year, and inclusive pages. Note that the item title is found only under the primary entry in the Author Index.