Tailoring The Interface Using Thiophene Small Molecules In Tio 2/p3ht Hybrid Solar Cells

In this paper we focus on the effect of carboxylated thiophene small molecules as interface modifiers in TiO 2/P3HT hybrid solar cells. Our results show that small differences in the chemical structure of these molecules, for example, the presence of the -CH 2- group in the 2-thiopheneacetic acid (TAA), can greatly increase the TiO 2 surface wettability, improving the TiO 2/polymer contact. This effect is important to enhance exciton splitting and charge separation. This journal is © 2012 the Owner Societies.14341199011993Huang, Y.-C., Hsu, J.-H., Liao, Y.-C., Yen, W.-C., Li, S.-S., Lin, S.-T., Chen, C.-W., Su, W.-F., (2011) J. Mater. Chem., 21, p. 4450Bouclé, J., Ravirajan, P., Nelson, J., (2007) J. Mater. Chem., 17, p. 3141Bhongale, C.J., Thelakkat, M., (2010) Sol. Energy Mater. Sol. Cells, 94, p. 817Bolognesi, M., Sánchez-Díaz, A., Ajuria, J., Pacios, R., Palomares, E., (2011) Phys. Chem. Chem. Phys., 13, p. 6105Arici, E., Meissner, D., Schaffler, F., Sariciftci, N.S., (2003) Int. J. Photoenergy, 5, p. 199Arici, E., Sariciftci, N.S., Meissner, D., (2003) Adv. Funct. Mater., 13, p. 165De Freitas, J.N., Grova, I.R., Akcelrud, L.C., Arici, E., Sariciftcic, N.S., Nogueira, A.F., (2010) J. Mater. Chem., 20, p. 4845Yella, A., Lee, H.-W., Tsao, H.N., Yi, C., Chandiran, A.K., Nazeeruddin, M.K., Diau, E.W.-G., Grätzel, M., (2011) Science, 334, p. 629Yu, Q., Wang, Y., Yi, Z., Zu, N., Zhang, J., Zhang, M., Wang, P., (2010) ACS Nano, 4, p. 6032Lin, Y.-Y., Chu, T.-H., Li, S.-S., Chuang, C.-H., Chang, C.-H., Su, W.-F., Chang, C.-P., Chen, C.-W., (2009) J. Am. Chem. Soc., 131, p. 3644Sun, Z., Li, J., Liu, C., Yang, S., Yan, F., (2011) Adv. Mater., 23, p. 3648Coakley, K.M., Srinvasan, B.S., Ziebarth, J.M., Goh, C., Liu, Y.X., McGehee, M.D., (2005) Adv. Funct. Mater., 15, p. 1927Huang, Y.-C., Yen, W.-C., Liao, Y.-C., Yu, Y.-C., Hsu, C.-C., Ho, M.-L., Chou, P.-T., Su, W.-F., (2010) Appl. Phys. Lett., 96, p. 123501Zhang, W., Zhu, R., Li, F., Wang, Q., Liu, B., (2011) J. Phys. Chem. C, 115, p. 7038Johansson, E.M.J., Scholin, R., Siegbahn, H., Hagfeldt, A., Rensmo, H., (2011) Chem. Phys. Lett., 515, p. 146Ravirajan, P., Peiró, A.M., Nazeeruddin, M.K., Grätzel, M., Bradley, D.D.C., Durrant, J.R., Nelson, J., (2006) J. Phys. Chem. B, 110, p. 7635Weickert, J., Dunbar, R.B., Hesse, H.C., Wiedemann, W., Mende, L.S., (2011) Adv. Mater., 23, p. 1810Chang, J.A., Rhee, J.H., Im, S.H., Lee, Y.H., Kim, H.-J., Seok, S.I., Nazeeruddin, M.K., Gratzel, M., (2010) Nano Lett., 10, p. 2609Jiang, X., Karlsson, K.M., Gabrielsson, E., Johansson, E.M.J., Quintana, M., Karlsson, M., Sun, L., Hagfeldt, A., (2011) Adv. Funct. Mater., 21, p. 2944Snaith, H.J., Moule, A.J., Klein, C., Meerholz, K., Friend, R.H., Grätzel, M., (2007) Nano Lett., 7, p. 3372Weickert, J., Auras, F., Bein, T., Mende, L.S., (2011) J. Phys. Chem. C, 115, p. 15081Liu, Y., Scully, S.R., McGehee, M.D., Liu, J., Luscombe, C.K., Frechet, J.M.J., Shaheen, S.E., Ginley, D.S., (2006) J. Phys. Chem. B, 110, p. 3257Chang, Y.-M., Su, W.-F., Wang, L., (2008) Macromol. Rapid Commun., 29, p. 1303Cantu, M.L., Chafiq, A., Faissat, J., Valls, I.G., Yu, Y., (2011) Sol. Energy Mater. Sol. Cells, 95, p. 1362Jiang, K.-J., Manseki, K., Yu, Y.-H., Masaki, N., Suzuki, K., Suzuki, Y.-L., Yanagida, S., (2009) Adv. Funct. Mater., 19, p. 2481Goh, C., Scully, S.R., McGehee, M.D., (2007) J. Appl. Phys., 101, p. 114503Krüger, J., Bach, U., Grätzel, M., (2000) Adv. Mater., 12, p. 447Montanari, I., Nogueira, A.F., Nelson, J., Durrant, J.R., Winder, C., Loi, M.A., Sariciftci, N.S., Brabec, C., (2002) Appl. Phys. Lett., 81, p. 3001Nogueira, A.F., Montanari, I., Nelson, J., Brabec, C., Sariciftci, N.S., Durrant, J.R., (2003) J. Phys. Chem., 107, p. 1567Haque, S.A., Palomares, E., Cho, B.M., Green, A.N.M., Hirata, N., Klug, D.R., Durrant, J.R., (2005) J. Am. Chem. Soc., 127, p. 3456Clifford, J.N., Palomares, E., Nazeeruddin, M.K., Grätzel, M., Nelson, J., Li, X., Long, J., Durrant, J.R., (2004) J. Am. Chem. Soc., 126, p. 5225Bouclé, J., Chyla, S., Shaffer, M.S.P., Durrant, J.R., Bradley, D.D.C., Nelson, J., (2008) Adv. Funct. Mater., 18, p. 62

Genetic evaluation of Jatropha curcas: an important oilseed for biodiesel production

Jatropha curcas, internationally and locally known, respectively, as physic nut and pinhão manso, is a highly promising species for biodiesel production in Brazil and other countries in the tropics. It is rustic, grows in warm regions and is easily cultivated. These characteristics and high-quality oil yields from the seeds have made this plant a priority for biodiesel programs in Brazil. Consequently, this species merits genetic investigations aimed at improving yields. Some studies have detected genetic variability in accessions in Africa and Asia. We have made the first genetic evaluation of J. curcas collected from Brazil. Our objective was to quantify genetic diversity and to estimate genetic parameters for growth and production traits and seed oil content. We evaluated 75 J. curcas progenies collected from Brazil and three from Cambodia. The mean oil content in the seeds was 31%, ranging from 16 to 45%. No genetic correlation between growth traits and seed oil content was found. However, high coefficients of genetic variation were found for plant height, number of branches, height of branches, and stem diameter. The highest individual narrow-sense heritabilities were found for leaf length (0.35) and width (0.34), stem diameter (0.24) and height of branches (0.21). We used a clustering algorithm to genetically identify the closest and most distant progenies, to assist in the development of new cultivars. Geographical diversity did not necessarily represent the genetic diversity among the accessions collected. These results are important for the continuity of breeding programs, aimed at obtaining cultivars with high grain yield and high oil content in seeds

Incorporation Of Nanocrystals With Different Dimensionalities In Hybrid Tio2/p3ht Solar Cells

We investigate the effect of TiO2 nanoparticles-nanospheres and nanorods-inserted in the poly(3-hexylthiophene) (P3HT) matrix of TiO2?P3HT inverted hybrid solar cells. X-ray diffraction, high-resolution transmission electron microscopy, small-angle x-ray scattering, photoluminescence, and photoelectrochemical experiments were employed to investigate the structure, morphology, and photoactivity of TiO2 nanoparticles modified with 2-thiopheneacetic acid, mixed or not with P3HT. Both TiO2 nanospheres and TiO2 nanorods presented a good dispersion in the polymer matrix. The incorporation of TiO2 nanospheres and nanorods has improved the photocurrent generation, and devices with efficiency values up to 1.35% were obtained. Our results reveal that the nanoscale morphology enables an enhanced interfacial area for exciton dissociation. 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Benthic organic matter transformation drives pH and carbonate chemistry in Arctic marine sediments

Carbonate chemistry of the Arctic Ocean seafloor and its vulnerability to ocean acidification remains poorly explored. This limits our ability to quantify how biogeochemical processes and bottom water conditions shape sedimentary carbonate chemistry, and to predict how climate change may affect such biogeochemical processes at the Arctic Ocean seafloor. Here, we employ an integrated data-model assessment that explicitly resolves benthic pH and carbonate chemistry along a S—N transect in the Barents Sea. We identify the main drivers of observed carbonate dynamics and estimate benthic fluxes of dissolved inorganic carbon and alkalinity to the Arctic Ocean. We explore how bottom water conditions and in-situ organic matter degradation shape these processes and show that organic matter transformation strongly impacts pH and carbonate saturation (Ω) variations. Aerobic organic matter degradation drives a negative pH shift (pH 5 at around 10–25 cm, model simulations result in authigenic carbonate precipitation. Furthermore, benthic fluxes of dissolved inorganic carbon (12.5—59.5 µmol cm−2 yr−1) and alkalinity (11.3—63.2 µmol cm−2 yr−1) are 2—3-fold greater in the northern sites due to greater carbonate dissolution. Our assessment is of significant relevance to predict how changes in the Arctic Ocean may shift carbon burial and pH buffering into the next century

The paleolimnologist's guide to compound-specific stable isotope analysis - An introduction to principles and applications of CSIA for quaternary lake sediments

The stable isotope composition of key chemical elements for life on Earth (e.g., carbon, hydrogen, nitrogen, oxygen, sulfur) tracks changes in fluxes and turnover of these elements in the biogeosphere. Over the past 15-20 years, the potential to measure these isotopic compositions for individual, source-specific organic molecules (biomarkers) and to link them to a range of environmental conditions and processes has been unlocked and amplified by increasingly sensitive, affordable and wide-spread analytical technology. Paleoenvironmental research has seen enormous step-changes in our understanding of past ecosystem dynamics. Vital to these paradigm shifts is the need for well-constrained modern and recent analogues. Through increased understanding of these environments and their biological pathways we can successfully unravel past climatic changes and associated ecosystem adaption. With this review, we aim to introduce scientists working in the field of Quaternary paleolimnology to the tools that compound-specific isotope analysis (CSIA) provides for the gain of information on biogeochemical conditions in ancient environments. We provide information on fundamental principles and applications of novel and established CSIA applications based on the carbon, hydrogen, nitrogen, oxygen and sulfur isotopic composition of biomarkers. While biosynthesis, sources and associated isotope fractionation patterns of compounds such as n-alkanes are relatively well-constrained, new applications emerge from the increasing use of functionalized alkyl lipids, steroids, hopanoids, isoprenoids, GDGTs, pigments or cellulose. Biosynthesis and fractionation are not always fully understood

Historical separation and present-day structure of common dolphinfish (Coryphaena hippurus) populations in the Atlantic Ocean and Mediterranean Sea

The common dolphinfish (Coryphaena hippurus) is an epipelagic, mid-trophic level, highly migratory species distributed throughout the world’s tropical and subtropical oceans in waters greater than 20C. Life-history variables, migratory behaviour, and genetic markers have been used to define major stocks in the central Atlantic Ocean and Mediterranean Sea. Here, we used the mitochondrial DNA gene NADH subunit 1 (688 bp) to test for differences between population groups. A total of 103 haplotypes were detected among 203 fish. Gene diversities in samples were large and similar among populations (mean h ¼ 0.932; range 0.894–0.987), but nucleotide diversities varied widely among samples (range p ¼ 0.004–0.034) and appear to reflect population histories. Principal component analysis revealed two large populations groups, and the analysis of molecular variation and pairwise values of UST resolved population structure within these groups. Populations in the eastern Atlantic and Mediterranean showed the largest amounts of divergence from one another (UCT ¼ 0.331). Adult movement and biophysical barriers to larval dispersal may explain contemporary differences between stocks, but the divergent populations in the Mediterranean Sea are likely due to isolations by cold temperature barriers during Pleistocene glaciations. The geographically large stock groupings require international cooperation in the harvest management and conservation of local dolphinfish populations