Keggin-Type PMo₁₁V as a P‑type Dopant for Enhancing the Efficiency and Reproducibility of Perovskite Solar Cells

The conventional perovskite solar cells (PSCs) with 2,2′,7,7′-tetrakis­(<i>N</i>,<i>N</i>-dimethoxyphenylamine)-9,9′-spirobifluorene (spiro-OMeTAD) as a hole transporting material commonly suffer from poor stability and reproducibility mainly due to the process of placing the devices in air and illumination for oxidizing the spiro-OMeTAD. Herein, Keggin-type polyoxometalates (POMs)-phosphovanadomolybdate (H₄PMo₁₁V·nH₂O, denoted as PMo₁₁V) is for the first time employed as a p-type dopant for promoting the oxidation of spiro-OMeTAD. Thereby, without illumination and air, the conductivity and hole extraction efficiency of the PMo₁₁V doped spiro-OMeTAD with assistance of lithium bis­(trifluoromethanesulfonyl)­imide (Li-TFSI) and 4-<i>tert</i>-butylpyridine (TBP) can be dramatically enhanced. On the basis of this strategy, the corresponding PSCs exhibit substantially improved photovoltaic performance and good reproducibility. The best performing device yields a power conversion efficiency (PCE) of 14.05%. This work indicates a great potential of polyoxometalates for further applications in solar cells and other optoelectronics devices

Self-Polarization in Epitaxial Fully Matched Lead-Free Bismuth Sodium Titanate Based Ferroelectric Thin Films

The Bi_0.5Na_0.5TiO₃-based ferroelectric is one of the most promising candidates for environment-friendly lead-free ferroelectric/piezoelectric materials for various applications such as actuators and micro-electromechanical systems. The understanding and tailoring of the ferro-(piezo-)­electric properties of thin films, however, are strongly hindered by the formation of the defects such as dislocations, ion vacancies in the film, as well as by the complexity of the interface between the film and the substrate. An ideal system for the study of the polarization behavior in the ferro-(piezo-)­electric film would be a fully matched system. In this work, monocrystalline 0.89Bi_0.5Na_0.5TiO₃–0.11BaTiO₃ thin films were epitaxially grown on (001)-oriented Nb-doped SrTiO₃ substrates using a sol–gel technique. The films were almost fully lattice- and thermally matched with the substrate, thus avoiding the impact of dislocations and thermal stress. The films were self-poled by a built-in electric field, originating from the sedimentation of heavier atoms during the film preparation. As a consequence, an upward self-polarization was introduced into the films, giving rise to asymmetric phase hysteresis loops and domain switching current responses. These results highlight the importance of the interface complexity for the self-polarization of piezoelectric thin films, even for fully matched films, which will therefore facilitate the control of properties of piezoelectric films and their applications for various functional devices

Prime pairs used in Realtime PCR.

<p>Prime pairs used in Realtime PCR.</p

Cell Viability Assay and Colony Assay.

<p>(A) Cells of each cancer cell line were treated with various concentrations of α-solanine for 24 h and 48 h. (B) Photos of anchorage-independent cell growth of PANC-1(100×magnification). (C) The colony number were quantified and data were calculated from three independent experiments. Each bar represents the means ± S.E.M. (n = 3). **p<0.01, compared with the control.</p

Effect of α-Solanine on expression of metastasis associated molecule.

<p>(A) The mRNA expression of MMP-2/9, EMMPRIN, CD44, ENOS and Ecadherin was presented as means ± S.E.M. of three independent experiments.(B) The expressions of MMP-2 and MMP-9 protein were analyzed by Western blot.(C) The expressions of Ecadherin protein was performed by Western blot.(D) Quantification of the western blot results were performed by calculating the ratio of the value to the control group.(E) The activity of MMP-2 and MMP-9 were analyzed by Gelatin Zymography. (F) Quantification of the Gelatin Zymography results were performed by calculating the ratio of the value to the control group. *p<0.05, **p<0.01, compared with the control. GAPDH was used as a loading control.</p

Cell Migration and Invasion Assays.

<p>Cells were treated with various concentrations of α-solanine for 24 h. (A) Cells were photographed(100×magnification). (B) The wound area were quantified in four fields in each treatment, and data were calculated from three independent experiments.(C) Cells were photographed(100×maginfication). (D) The invaded cells were quantified by counting fo DAPI-stained cells. Each bar represents the means ± S.E.M. (n = 3).*p<0.05, **p<0.01, compared with the control.</p

Effect of α-solanine on the expression of MMP-2, MMP-9, PCNA and VEGF in PANC-1 tumor xenograft.

<p>When tumor xenografts were seperated, parts of tumor were used for Western blot and Immunohistochemistry. (A) The expressions of MMP-2 and MMP-9 protein were analyzede by Western blot. (B,C) Tumor tissus were innunohistochemically analyzed for PCNA-positive cells and VEGF staining density. Representative photographs of IHC staining of PCNA and VEGF are shown at 400×magnifications. Scale bar: 50 µm. The data are presented as the mean ± SE. *p<0.05, **p<0.01, compared with the control.</p

Effect of α-solanine on the PANC-1 tumor xenograft growth and body weight of athymic nude mice.

<p>PANC-1 cells were subcutaneously injected into the flanks of nude mice. When the tumors were measurable, mice were given DMSO or α-solanine for 2 weeks. (A) Tumor volume/mouse as a function of time.(B) The mouse of each group was monitored for body weight once a day. Mean body weight/mouse as a function of time.(C) Tumor volume/mouse and (D) tumor weight/mouse at the end of the study were analyzed. *p<0.05, compared with the control.</p

Effect of α-solanine on phosphorylation of Akt and mTOR.

<p>PANC-1 cells were treated with various doses of α-solanine for 24 h, or 9 µg/µl of α-solanine for 6,12,18,24 h. (A,C) The phosphorylation level of Akt and mTOR were determined by Western blot. GAPDH was used as a loading control. (B,D) Quantification of the western blot results were performed by calculating the ratio of the value to the control group. *p<0.05, **p<0.01, compared with the control.</p

Effect of α-solanine on the expression of NF-κB/p65, β-catenin and TCF-1 in nucleus of PANC-1 cells.

<p>PANC-1 cells were treated with various doses of α-solanine for 24 h. (A,C) The level of NF-κB/p65, β-catenin and TCF-1 in nucleus were determined by Western blot. Laminb1 was used as a nuclear protein loading control. (B,D) Quantification of the densitometric results were performed by calculating the ratio of the value to the control group. *p<0.05, **p<0.01, compared with the control.</p