Algorithm based high composition-controlled growths of GeSn on GaAs (001) via molecular beam epitaxy

The growth of high-composition GeSn films of the future will likely be guided via algorithms. In this study we show how a logarithmic-based algorithm can be used to obtain GeSn compositions up to 16 % on GaAs (001) substrates via molecular beam epitaxy. Within we demonstrate composition targeting and logarithmic gradients to achieve pseudomorph GeSn compositions near 11% before partial relaxation of the structure and a continued gradient to 16 % GeSn. Using algorithmic-based control and calibration, the ability to consistently and easily grow GeSn compositions above 20 % will likely become very possible. In this report, we use X-ray diffraction and atomic force microscopy to analyze and demonstrate some of the possible growths that can be produced with the enclosed algorithm

Facile Bulk Synthesis of pi Cubic SnS

The cubic modification of binary tin sulfide SnS has gained significant interest as an earth abundant, low toxicity solar absorber material with a band gap close to the optimal value for the conversion of sunlight. We herein report a simple synthesis for the metastable material, which will allow more elaborate characterization methods to be used on this material, and present a full powder refinement of the material along with some preliminary results on the optical and thermal stability propertie

Dualities of Latin America

Determining whether the current situation of Latin America is better described as "post-neoliberalism" or as "commodities consensus" requires an analysis of recent changes in the region. Capitalism has expanded in agriculture and mining, accentuating the preeminence of basic exports. Traditional industry is declining, and remittances and tourism have increased in importance. Local capitalists associated with foreign corporations have replaced the national bourgeoisie, while the exodus of peasants consolidates labor precariousness, poverty, and inequality. At the same time, the United States is deploying troops to reorganize its domination. The South American rebellions have limited neoliberal aggression and achieved unusual victories in other parts of the world. The concept of post-neoliberalism emphasizes the region's political turn toward autonomy but overlooks the persistence of the economic model generated during the previous phase. The opposing concept, commodities consensus, highlights the extractivism prevailing throughout the region but plays down the extreme divergences among right-wing, center-left, and radical governments in all other areas. Both concepts contain part of the truth, but neither fully explains the regional scenario.Para determinar si la situación actual de Latinoamérica es mejor descrita como “postneoliberalismo” o como un “consenso de los commodities” hay que hacer un análisis de los cambios recientes en la región. El capitalismo se ha expandido en la agricultura y la minería, acrecentando la preeminencia de las exportaciones básicas. La industria tradicional ha disminuido, y la importancia del turismo y las remesas ha aumentado. Los capitalistas locales asociados con empresas extranjeras han reemplazado a la burguesía nacional, mientras que el éxodo de los campesinos ha consolidado la precariedad laboral, la pobreza y la desigualdad. Al mismo tiempo, Estados Unidos despliega tropas para reorganizar su dominio. Las rebeliones en América del Sur han puesto barreras a la agresión neoliberal y logrado victorias inusuales en otras partes del mundo. El concepto del postneoliberalismo destaca el giro político de la región hacia la autonomía pero con una tendencia a la persistencia del modelo económico generado durante la fase anterior. El otro concepto, el consenso de las commodities, destaca el extractivismo que prevalece en toda la región pero minoriza las divergencias entre los gobiernos de derecha, centro-izquierda y radicales en todas las demás áreas. Ambos conceptos son parcialmente ciertos, pero no explican totalmente el escenario regional.Fil: Katz, Claudio Isaac. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Analysis of grain orientation and defects in Sb2Se3 solar cells fabricated by close spaced sublimation

The performance of a superstrate TiO2 Sb2Se3 solar cell, fabricated by close spaced sublimation technique CSS , was improved after the deployment of a seed layer. The seed layer caused columnar Sb2Se3 film growth with texture coefficient analysis TC showing increased presence of crystal planes, which are inclined towards the [001] crystal direction. Given the highly anisotropic properties of Sb2Se3, preferential growth of Sb4Se6 n rib bons along the [001] direction is best suited for effective charge collection. Hence, grain orientation of Sb2Se3 films was studied more closely via measurement of pole figures by XRD and orientation distribution maps by electron backscatter diffraction EBSD . Although the measurements did not reveal strong preferred orientation, it was observed that the columnar Sb2Se3 growth enhanced texture along the [001] direction. Temperature dependent admittance spectroscopy TAS and capacitance voltage CV profiling were performed on the seed assisted TiO2 Sb2Se3 solar cell to evaluate carrier density and deep defects in the Sb2Se3 absorber. TAS study revealed a deep defect with activation energy of 0.39 eV. CV profiles indicated that the density of defects could be as high as 1017 c

`China Design Now'

This article draws from cultural studies, political theory, international relations, art history and museum studies in order to consider `China Design Now' — the blockbuster exhibition, recently held at the V&A. It argues that, despite the inclusion of a number of interesting exhibits, the attempt to frame contemporary Chinese design independently of political contextualization has led to an exhibition which is largely unsatisfying. The approach taken by the V&A is further shown to have produced several ironic outcomes. First, by attempting to avoid `contentious' political issues, the museum has, in fact, forced the `political' to the fore. Second, by taking such an approach, the V&A demonstrates that it has failed to understand the essentially political nature of the design problem. Third, it has produced an exhibition which appears to advocate a (highly political) neoliberal agenda — one which insists on an inexorable drive towards greater global economic integration. Finally, it has failed to mention its own embeddedness within larger strategies of `cultural diplomacy' and the significance of such strategies for international relations and for cultural production. As well as drawing on a range of relevant literature, the article makes direct reference to exhibition wall texts, exhibit labels and quotations from the catalogue in order to support its argument