Reduced trap-density and boosted performance of CH3NH3PbI3solar cells by 1-Pentanethiol enhanced anti-solvent washing route.

Performance and the stability of the perovskite-based photovoltaic devices are directly linked to existing trap-states or defect profiles at the surface and/or in the bulk of perovskite layers. Hence identification of stemming the defects during perovskite formation is crucial for achieving superior and long-lasting performances. Here, we present the effect of 1-Pentanethiol incorporation into the one-step deposition of perovskite layers. A feasible glove box-free route results in high-quality CH3NH3PbI3layers under highly humid conditions (RH > 50%) but at low temperatures (T< 18 °C). 1-Pentanethiol addition into the washing solvent leads to the refinement of I/Pb stoichiometry, elimination of the iodide deficiencies, and reduction of the trap-state densities. Consequently, a precise amount 1-Pentanethiol addition enhances photovoltaic performances, resulting in a 54% PCE improvement for CH3NH3PbI3-based inverted solar cells.

Influences of CdSe NCs on the photovoltaic parameters of BHJ organic solar cells.

In this study, the high quality CdSe nanocrystals (NCs) capped with stearic acid were synthesized in a solvent and then purified four times by using the precipitation and redissolution process. The average size of the synthesized CdSe NCs was determined ~3.0nm via transmission electron microscopy (TEM) measurement and their corresponding optical band edge energy was also calculated as ~2.1eV using ultraviolet-visible (UV-Vis) absorption spectroscopy. The bulk heterojunction (BHJ) hybrid solar cells based on a ternary system including P3HT, PCBM and CdSe NCs at different weight concentrations (0wt%, 0.1wt%, 0.5wt%, 1wt% and 2wt%) were fabricated by spin-casting process. The effect of the concentration of CdSe NCs on the photovoltaic parameters of these BHJ organic solar cells was investigated. The surface morphology of the photoactive layer modified by the incorporation of CdSe NCs into P3HT:PCBM matrix was observed with scanning electron microscopy (SEM). It was shown that when the concentration of CdSe NCs increases above 0.1wt% in this ternary system, the photovoltaic performance of the devices significantly decreases. The power conversion efficiency of the organic photovoltaic (OPV) device was enhanced ~20% by incorporating CdSe NCs with 0.1wt% with respect to those without CdSe NCs.

Metal-free polymer/MWCNT composite fiber as an efficient counter electrode in fiber shape dye-sensitized solar cells.

Highly aligned multiwall carbon nanotubes (MWCNT) as fiber were modified with a conducting polymer via a simple dip coating method. Modified MWCNT exhibited admirable improvement in electrocatalytic activity for the reduction of tri-iodide in dye sensitized solar cells. Scanning electron microscopy images confirm the successful deposition of polymer on MWCNT. Cyclic voltammetry, square wave voltammetry and electrochemical impedance spectroscopy studies were carried out to investigate the inner mechanism for the charge transfer behaviour. Results from bare and modified electrodes revealed that the MWCNT/(poly (3,4-ethylene dioxythiophene):poly(styrene sulfonate) ( PEDOT: PSS) composite electrode is much better at catalysing the [Formula: see text] redox couple compared to the pristine fiber electrode. The photoelectric conversion efficiency of 5.03% for the modified MWCNT electrodes was comparable with that of the conventional Pt-based electrode. The scientific results of this study reveal that MWCNT/PEDOT:PSS may be a better choice for the replacement of cost intensive electrode materials such as platinum. Good performance even after bending up to 90° and in-series connection to enhance the output voltage were also successfully achieved, highlighting the practical application of this novel device.

Theoretical and experimental investigations of the 2-(4-chlorophenyl)-3-{[5-(2-cyano-2-phenylethenyl)]furan-2-yl}acrylonitrile molecule as a potential acceptor in organic solar cells.

A novel soluble asymmetric acrylonitrile derivative, 2-(4-Chlorophenyl)-3-{[5-(2-cyano-2-phenylethenyl)]furan-2-yl}acrylonitrile (CPCPFA, 3) was synthesized in three steps by Knoevenagel condensation. The structure of the CPCPFA was characterized using UV-vis, FTIR, (1)H NMR, (13)C NMR, and LC-MS. CPCPFA was evaluated as an electron acceptor in bulk heterojunction organic solar cells. Its optical and electronic properties as well as photovoltaic performance were investigated.

Photovoltaic characterization of hybrid solar cells using surface modified TiO(2) nanoparticles and poly(3-hexyl)thiophene.

We report on the photovoltaic performance of bulk heterojunction solar cells using novel nanoparticles of 6-palmitate ascorbic acid surface modified TiO(2) as an electron acceptor embedded into the donor poly(3-hexyl)thiophene (P3HT) matrix. Devices were fabricated by using P3HT with varying amounts of red TiO(2) nanoparticles (1:1, 1:2, 1:3 w-w ratio). The devices were characterized by measuring current-voltage characteristics under simulated AM 1.5 conditions. Incident photon to current efficiency (IPCE) was spectrally resolved. The nanoscale morphology of such organic/inorganic hybrid blends was also investigated using atomic force microscopy (AFM).

Targeting of tumor cells expressing the prostate stem cell antigen (PSCA) using genetically engineered T-cells.

BACKGROUND: Curative therapeutic options for minimal residual disease or advanced tumor stages in prostate cancer (PCa) are still missing. Adoptive transfer of cytotoxic T-cells that have been polyclonally rendered tumor-specific by genetic engineering appears to be a promising immunotherapeutic strategy. Among the numerous prostate tissue/tumor antigens identified during the last years, the "prostate stem cell antigen" (PSCA) is an attractive immunotherapeutic target. It is broadly expressed on the surface of primary PCa cells as well as on PCa metastases. METHODS: To generate a chimeric T-cell receptor (TCR) recognizing PSCA, a monoclonal anti-PSCA antibody was raised and a single-chain fragment (scFv) was prepared. The resulting anti-PSCA scFv 7F5 was fused to the beta2 constant region derived from the beta-chain of a TCR and to the CD3zeta-signaling domain. RESULTS: The chimeric alpha-PSCA-beta2/CD3zeta-TCR, expressed in Jurkat cells, was phosphorylated in the ITAMs of the CD3-zeta chain upon cross-linking by insolublized PSCA. When transduced into a mouse cytotoxic T-cell line, the chimeric receptor specifically activated cytotoxicity against PSCA-positive tumor cells. CONCLUSIONS: We developed a functional chimeric TCR against PSCA for treatment of PCa. The chimeric alpha-PSCA-beta2/CD3zeta-TCR might now be used for arming human cytotoxic T-cells for further studies towards a clinical treatment of PCa.

Nuclear localization of Survivin renders HeLa tumor cells more sensitive to apoptosis by induction of p53 and Bax.

Clinical studies have shown that nuclear expression of the inhibitor of apoptosis protein Survivin in tumor cells predicted a favorable prognosis whereas cytosolic-localized protein caused a decreased overall survival. Therefore Survivin's subcellular localization may be important for its anti-apoptotic capacity. To address this question, we investigated localization and function of Survivin in normal human lung fibroblasts (NHLFs) and HeLa tumor cells. NHLFs of early passages expressed Survivin in the nucleus and were highly sensitive to C2 ceramide, which induces the mitochondrial apoptotic pathway. In contrast, NHLFs at higher passages relocated Survivin to the cytosol and became more resistant to C2 ceramide. Blocking nuclear export of Survivin by leptomycin B in HeLa cells increased susceptibility to C2 ceramide. In addition, transduction of HeLa cells with Survivin fused to a nuclear localization signal augmented basal expression levels of p53 and Bax and enhanced sensitivity for intrinsic apoptosis. Those findings suggest that a predominant nuclear localization of Survivin increases the sensitivity for pro-apoptotic stimuli, whereas nuclear export enables Survivin to fulfill its inhibitor of apoptosis function. A therapeutic intervention which holds Survivin in the nucleus of tumor cells might improve cancer therapy.