@article{GuerreroRamirezCravenReichetal.2017, author = {Guerrero-Ramirez, Nathaly Rokssana and Craven, Dylan and Reich, Peter B. and Ewel, John J. and Isbell, Forest and Koricheva, Julia and Parrotta, John A. and Auge, Harald and Erickson, Heather E. and Forrester, David I. and Hector, Andy and Joshi, Jasmin Radha and Montagnini, Florencia and Palmborg, Cecilia and Piotto, Daniel and Potvin, Catherine and Roscher, Christiane and van Ruijven, Jasper and Tilman, David and Wilsey, Brian and Eisenhauer, Nico}, title = {Diversity-dependent temporal divergence of ecosystem functioning in experimental ecosystems}, series = {Nature ecology \& evolution}, volume = {1}, journal = {Nature ecology \& evolution}, number = {11}, publisher = {Nature Publ. Group}, address = {London}, issn = {2397-334X}, doi = {10.1038/s41559-017-0325-1}, pages = {1639 -- 1642}, year = {2017}, abstract = {The effects of biodiversity on ecosystem functioning generally increase over time, but the underlying processes remain unclear. Using 26 long-term grassland and forest experimental ecosystems, we demonstrate that biodiversity-ecosystem functioning relationships strengthen mainly by greater increases in functioning in high-diversity communities in grasslands and forests. In grasslands, biodiversity effects also strengthen due to decreases in functioning in low-diversity communities. Contrasting trends across grasslands are associated with differences in soil characteristics.}, language = {en} } @article{BraungerMundtWolffetal.2018, author = {Braunger, Steffen and Mundt, Laura E. and Wolff, Christian Michael and Mews, Mathias and Rehermann, Carolin and Jost, Marko and Tejada, Alvaro and Eisenhauer, David and Becker, Christiane and Andres Guerra, Jorge and Unger, Eva and Korte, Lars and Neher, Dieter and Schubert, Martin C. and Rech, Bernd and Albrecht, Steve}, title = {Cs(x)FA(1-x)Pb(l(1-y)Br(y))(3) Perovskite Compositions}, series = {The journal of physical chemistry : C, Nanomaterials and interfaces}, volume = {122}, journal = {The journal of physical chemistry : C, Nanomaterials and interfaces}, number = {30}, publisher = {American Chemical Society}, address = {Washington}, issn = {1932-7447}, doi = {10.1021/acs.jpcc.8b06459}, pages = {17123 -- 17135}, year = {2018}, abstract = {We report on the formation of wrinkle-patterned surface morphologies in cesium formamidinium-based Cs(x)FA(1-y)Pb(I1-yBry)(3) perovskite compositions with x = 0-0.3 and y = 0-0.3 under various spin-coating conditions. By varying the Cs and Br contents, the perovskite precursor solution concentration and the spin-coating procedure, the occurrence and characteristics of the wrinkle-shaped morphology can be tailored systematically. Cs(0.17)FA(0.83)Pb(I0.83Br0.17)(3) perovskite layers were analyzed regarding their surface roughness, microscopic structure, local and overall composition, and optoelectronic properties. Application of these films in p-i-n perovskite solar cells (PSCs) with indium-doped tin oxide/NiOx/perovskite/C-60/bathocuproine/Cu architecture resulted in up to 15.3 and 17.0\% power conversion efficiency for the flat and wrinkled morphology, respectively. Interestingly, we find slightly red-shifted photoluminescence (PL) peaks for wrinkled areas and we are able to directly correlate surface topography with PL peak mapping. This is attributed to differences in the local grain size, whereas there is no indication for compositional demixing in the films. We show that the perovskite composition, crystallization kinetics, and layer thickness strongly influence the formation of wrinkles which is proposed to be related to the release of compressive strain during perovskite crystallization. Our work helps us to better understand film formation and to further improve the efficiency of PSCs with widely used mixed-perovskite compositions.}, language = {en} }