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1.
ACS Appl Mater Interfaces ; 12(47): 53021-53028, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33170610

RESUMO

As a well-known electron-withdrawing group, benzo[c][1,2,5]thiadiazole (BT) has been intensively studied and adopted to construct polymer donors with tunable band gaps. However, polymer solar cells (PSCs) with BT-based polymer donors, limited by the weak absorption and inflexible energy level of fullerene derivatives, usually suffer mediocre power conversion efficiencies (PCEs). Here, through subtly tailoring a BT unit with asymmetric fluoro and alkyloxy groups and judiciously pairing a BT-based polymer donor with three narrow band gap non-fullerene acceptors (e.g., IEICO-4F, ITOIC-2F, and IDTCN-O), active layers with complementary absorption spectra, small lowest unoccupied molecular orbital (LUMO) offsets, and preferred morphologies have been achieved. Consequently, PSCs with excellent Jsc values (over 20 mA/cm2) and high PCEs up to 12.33% have been obtained. To the best of our knowledge, the value of 12.33% is among the highest PCEs for BT-based polymers in binary PSCs so far. This work demonstrates that the cooperative effect of energy levels, absorption spectra, and morphologies between the donors and acceptors is crucial for governing the performance of organic photovoltaics.

2.
ACS Appl Mater Interfaces ; 12(36): 40590-40598, 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32805919

RESUMO

In this work, a ternary blend strategy based on PBDB-T and two small molecular acceptors (IDTT-OB and IDT-PDOT-C6) is demonstrated to simultaneously improve the photocurrent and reduce the voltage loss in organic solar cells (OSCs). The improved photocurrent is partially due to a broad absorption spectrum of the active layer. In addition, we find that the ternary system possesses a higher degree of crystallinity, smaller domain size, higher domain purity, and higher and more balanced charge-carrier mobilities in comparison with the two corresponding binary systems. The reduced voltage loss in the ternary device is mainly due to a lower energy loss (Eloss) of charge carriers. We achieve a Eloss of only 0.50 eV, which is one of the lowest values reported for the ternary nonfullerene OSCs. Our results have demonstrated that all photovoltaic parameters of ternary OSCs can be simultaneously improved by elaborately selecting the three active layer components.

3.
ACS Appl Mater Interfaces ; 12(33): 37409-37417, 2020 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-32814394

RESUMO

Three hexapod-shaped PDI-hexamers (PSM1, PSM2, and PSM3) with a diphenylmethylene-bridged triphenylamine (TPA) core and six peripheral PDI subunits have been designed and synthesized. The influence of different peripheral PDI subunits on the morphology and crystallinity of acceptors is investigated. Distinctly different from the previously reported PDI trimers with a TPA core, which exhibit amorphous morphologies, these hexapod-shaped acceptors display improved crystallinities and photophysical properties. Our studies have shown that PSM3 with six peripheral thiophene-fused PDI subunits gives the best result. The as-cast blend films of PBDB-T and PSM3, which possess appropriate phase separation and higher crystallinity, show high and balanced charge mobilities. As expected, OSCs with PBDB-T:PSM3 as the active layer achieve the highest power conversion efficiency of 6.71% among these three acceptors, which is the highest one in TPA-based acceptors and one of the best for the as-cast OSCs based on PDI derivatives.

4.
Nat Commun ; 10(1): 3038, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31292441

RESUMO

Non-fullerene fused-ring electron acceptors boost the power conversion efficiency of organic solar cells, but they suffer from high synthetic cost and low yield. Here, we show a series of low-cost noncovalently fused-ring electron acceptors, which consist of a ladder-like core locked by noncovalent sulfur-oxygen interactions and flanked by two dicyanoindanone electron-withdrawing groups. Compared with that of similar but unfused acceptor, the presence of ladder-like structure markedly broadens the absorption to the near-infrared region. In addition, the use of intramolecular noncovalent interactions avoids the tedious synthesis of covalently fused-ring structures and markedly lowers the synthetic cost. The optimized solar cells displayed an outstanding efficiency of 13.24%. More importantly, solar cells based on these acceptors demonstrate very low non-radiative energy losses. This research demonstrates that low-cost noncovalently fused-ring electron acceptors are promising to achieve high-efficiency organic solar cells.

5.
Front Chem ; 7: 333, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31157206

RESUMO

Fluorination of conjugated polymers is an effective strategy to tune the energy levels for obtaining high power conversion efficiency (PCE) in organic solar cells. In this work, we have developed fluoro-modulated molecular geometries in diketopyrrolopyrrole based low-bandgap copolymers. In these polymers, planar conformation can be locked by intramolecular non-covalent interaction (intramolecular supramolecular interaction) between the sulfur atoms and the introduced F atoms (F···S interaction). By varying the fluorinated moieties, such a planarity can be disturbed and the molecular geometry is tuned. As a result, the polymer' properties can be modulated, including the ultraviolet-visible absorption spectrum to become broaden, charge mobility to be enhanced, open-circuit voltage (V oc) and short-circuited current (J sc) to be elevated, and thus photovoltaic performance to be improved. The photovoltaic device based on PCFB, one of the fluorinated terpolymers, exhibited a high PCE near 8.5% with simultaneously enhanced V oc and J sc relative to the non-fluorinated one (PCB).

6.
ACS Appl Mater Interfaces ; 11(21): 19444-19451, 2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31060351

RESUMO

Two A-π-D-π-A-type non-fullerene acceptors (IDT-ToFIC and IDT-TiFIC) with 5-hexylthienyl chains substituted at the inner and outer ß-positions of the thiophene π-bridge have been designed, respectively. Impacts of varied positional modifications are systematically studied. By utilizing PBDB-T as the donor, polymer solar cells are constructed with these two molecules as acceptors. Power conversion efficiencies of 11.09 and 9.46% are acquired for IDT-ToFIC- and IDT-TiFIC-based devices, respectively. Our studies have demonstrated that the use of thiophene spacers carrying one conjugated side chain at different positions can markedly enhance the photovoltaic properties relative to the corresponding control molecule IDTT2F.

7.
ACS Appl Mater Interfaces ; 11(3): 3098-3106, 2019 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-30585714

RESUMO

A nonfullerene acceptor, IDTT-OB, employing indacenodithieno[3,2- b]thiophene (IDTT) decorated with asymmetric substituents as the core, is designedly prepared. In comparison with the analogue IDT-OB, extending the five-heterocyclic indacenodithiophene (IDT) core to seven-heterocyclic fused ring endows IDTT-OB with more broad absorption and elevated highest occupied molecular orbital energy level. In addition, IDTT-OB shows a more intense molecular packing and a higher crystalline behavior with a strong face-on orientation in the neat film and the PBDB-T:IDTT-OB blend film. Furthermore, an ideal nanomorphology with a domain size of 19 nm can be obtained, which is in favor of exciton diffusion and charge separation. Accordingly, PBDB-T:IDTT-OB-based polymer solar cells demonstrate a maximum power conversion efficiency (PCEmax) of 11.19% with an impressive fill factor of 0.74, comparable to the state-of-the-art acceptors with similar molecular backbones. More importantly, IDTT-OB-based devices show good tolerance to the film thickness, which maintain a high PCE of 10.20% with a 250 nm thick active layer, demonstrating that the asymmetric acceptor is profound for fabricating high-efficiency thick-film nonfullerene solar cells.

8.
Adv Mater ; 29(42)2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28960559

RESUMO

A kind of new fused-ring electron acceptor, IDT-OB, bearing asymmetric side chains, is synthesized for high-efficiency thick-film organic solar cells. The introduction of asymmetric side chains can increase the solubility of acceptor molecules, enable the acceptor molecules to pack closely in a dislocated way, and form favorable phase separation when blended with PBDB-T. As expected, PBDB-T:IDT-OB-based devices exhibit high and balanced hole and electron mobility and give a high power conversion efficiency (PCE) of 10.12%. More importantly, the IDT-OB-based devices are not very sensitive to the film thickness, a PCE of 9.17% can still be obtained even the thickness of active layer is up to 210 nm.

9.
ACS Appl Mater Interfaces ; 9(39): 33906-33912, 2017 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-28895729

RESUMO

Three indacenodithieno[3,2-b]thiophene (IT) cored small molecular acceptors (ITIC-SC6, ITIC-SC8, and ITIC-SC2C6) were synthesized, and the influence of side chains on their performances in solar cells was systematically probed. Our investigations have demonstrated the variation of side chains greatly affects the charge dissociation, charge mobility, and morphology of the donor:acceptor blend films. ITIC-SC2C6 with four branched side chains showed improved solubility, which can ensure the polymer donor to form favorable fibrous nanostructure during the drying of the blend film. Consequently, devices based on PBDB-ST:ITIC-SC2C6 demonstrated higher charge mobility, more effective exciton dissociation, and the optimal power conversion efficiency up to 9.16% with an FF of 0.63, a Jsc of 15.81 mA cm-2, and a Voc of 0.92 V. These results reveal that the side chain engineering is a valid way of tuning the morphology of blend films and further improving PCE in polymer solar cells.

10.
Acta Biochim Biophys Sin (Shanghai) ; 38(3): 157-63, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16518539

RESUMO

Cytotoxic T lymphocytes (CTLs) specific for the Epstein-Barr virus (EBV) latent membrane protein 2 (LMP2) antigen are important reagents for the treatment of some EBV-associated malignancies, such as EBV-positive Hodgkin's disease and nasopharyngeal carcinoma. However, the therapeutic amount of CTLs is often hampered by the limited supply of antigen-presenting cells. To address this issue, an artificial antigen-presenting cell (aAPC) was made by coating a human leukocyte antigen (HLA)-pLMP2 tetrameric complex, anti-CD28 antibody and CD54 molecule to a cell-sized latex bead, which provided the dual signals required for T cell activation. By co-culture of the HLA-A2-LMP2 bearing aAPC and peripheral blood mononuclear cells from HLA-A2 positive healthy donors, LMP2 antigen-specific CTLs were induced and expanded in vitro. The specificity of the aAPC-induced CTLs was demonstrated by both HLA-A2-LMP2 tetramer staining and cytotoxicity against HLA-A2-LMP2 bearing T2 cell, the cytotoxicity was inhibited by the anti-HLA class I antibody (W6/32). These results showed that LMP2 antigen-specific CTLs could be induced and expanded in vitro by the HLA-A2-LMP2-bearing aAPC. Thus, aAPCs coated with an HLA-pLMP2 complex, anti-CD28 and CD54 might be promising tools for the enrichment of LMP2-specific CTLs for adoptive immunotherapy.


Assuntos
Células Apresentadoras de Antígenos/metabolismo , Infecções por Vírus Epstein-Barr/tratamento farmacológico , Antígenos HLA/metabolismo , Leucócitos/imunologia , Linfócitos T Citotóxicos/imunologia , Proteínas da Matriz Viral/imunologia , Células Apresentadoras de Antígenos/citologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Antígenos HLA/química , Antígeno HLA-A2/imunologia , Doença de Hodgkin/tratamento farmacológico , Doença de Hodgkin/imunologia , Doença de Hodgkin/patologia , Humanos , Molécula 1 de Adesão Intercelular/imunologia , Molécula 1 de Adesão Intercelular/metabolismo , Leucócitos/química , Neoplasias Nasofaríngeas/tratamento farmacológico , Neoplasias Nasofaríngeas/imunologia , Neoplasias Nasofaríngeas/patologia , Células Tumorais Cultivadas
11.
Cell Mol Immunol ; 3(6): 453-8, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17257499

RESUMO

HLA-A2 is the most frequent HLA-A allele in all ethnic populations, and an important restriction element for peptide presentation to T cells in infectious disease and cancer. However, the HLA-A2 supertype consisting of up to 75 subtypes, mutation studies and analyses using cytotoxic T lymphocytes suggest the functional relevance of subtype-specific differences in HLA-A2 molecules for peptide binding and T-cell recognition. Therefore, it is necessary for T-cell response study to discriminate the HLA-A2 subtypes and to understand the profile of HLA-A2 allelic distribution in a given population. In this study, we developed a simple, robust approach based on the nested polymerase chain reaction using sequence-specific primers (PCR-SSP) to discriminate 17 HLA-A2 subtypes which cover the most HLA-A2 alleles (> 99% allele frequency) reported in Chinese, using 15 combinations of 19 allelic specific primers. In the first round of PCR, 3 combinations of 5 primers were used to determine whether the tested sample was HLA-A2 positive, meanwhile the subtypes of HLA-A*0209 and HLA-A*0215N were determined for the variant position of these two subtypes is in exon 4 instead of exon 2, 3. Samples of HLA-A2 positive were subtyped in the second round of PCR, using PCR products of the first round as templates. This strategy was applied to test the samples of 78 random HLA-A2 positive individuals for their HLA-A2 subtypes. Those samples were screened for HLA-A2 positive by the first round PCR-SSP from 154 healthy blood donors in Wuhan, China. The subtyping results were verified by using flow cytometric analysis (FCM) with HLA-A2 specific monoclonal antibody BB7.2 and DNA sequencing. The typing results of the samples show 50.7% random individuals in the population carry HLA-A2, HLA-A*0201 ranks the first (allele frequency = 15.5%), followed by A*0207 (5.8%), A*0206 (4.7%), A*0203 (2.6%), A*0210 (0.7%), and these 5 alleles account for 99.0% HLA-A2 subtypes of allele frequency. Our study indicates that the developed typing method is simple and reliable for HLA-A2 subtyping in Chinese, and the profile of allelic distribution of HLA-A2 subtypes is revealed in the population of Wuhan, China.


Assuntos
Antígeno HLA-A2/classificação , Antígeno HLA-A2/genética , Reação em Cadeia da Polimerase , China , Humanos
12.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 21(6): 676-8, 2005 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-16256023

RESUMO

AIM: To study the effect of HLA-G1 molecule expressed by an endothelial cell line (ECV304) on the cytotoxic activity of allogeneic NK cells. METHODS: ECV304 cells were transfected with recombinant plasmid pcDNA3-HLA-G1 by the liposome transfection, and the expressed HLA-G1 on the cell surface was detected by indirect immunofluorescent assay and flow cytometry. The cytotoxic activity of allogeneic NK cells against ECV304 cells was analyzed by the MTT method. RESULTS: HLA-G1 was expressed on the surface of the transfected ECV304 cells. The specific lysis of NK cells against plasmid pcDNA3 transfected ECV304 was (50.6+/-18.1)%, while the specific lysis against pcDNA3-HLA-G1 transfected ECV304 was (29.7+/-11.4)%, which was significantly lower than the former (P<0.001). CONCLUSION: HLA-G1 expressed by the ECV304 cells can inhibit cytotoxicity of allogeneic NK cells.


Assuntos
Antígenos HLA/imunologia , Antígenos HLA/metabolismo , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/fisiologia , Linhagem Celular , Células Cultivadas , Testes Imunológicos de Citotoxicidade , Citometria de Fluxo , Técnica Indireta de Fluorescência para Anticorpo , Vetores Genéticos/genética , Antígenos HLA/genética , Antígenos HLA-G , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Lipossomos , Transfecção
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