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Cd1-xZnxS thin films have been studied extensively as window layers for solar cell applications. However, a mismatch between the Cd1-xZnxS and copper-indium-gallium-selenide absorber layers increases with Zn film concentration, which reduces the device efficiency. In this work, Cd1-xZnxS thin films with low Zn concentrations were analyzed. The effect of the addition of different molar Zn concentrations to the reaction mixture on the growth mechanism of Cd1-xZnxS thin films and the influence of these mechanisms on structural, optical and morphological properties of the films has been studied. Cd1-xZnxS thin films were synthesized by chemical bath deposition using an ammonia-free alkaline solution. Microstructural analysis by X-ray diffraction showed that all deposited films grew with hexagonal structure and crystallite sizes decreased as the Zn concentration in the film increased. Optical measurements indicated a high optical transmission between 75% and 90% for wavelengths above the absorption edge. Band gap value increased from 2.48 eV to 2.62 eV, and the refractive index values for Cd1-xZnxS thin films decreased as the Zn increased. These changes in films and properties are related to a modification in growth mechanism of the Cd1-xZnxS thin films, with the influence of Zn(OH)2 formation being more important as Zn in solution increases.

This article questions several aspects of current development policies in the Amazon. The central argument is that the knowledge of the region is essential for achieving sustainable development. Thirteen points are discussed to stimulate debate, and these are: the invention of the Amazon; regional inequalities; knowledge as a factor of development; investment in education, science and technology; the brain drain; traditional knowledge; the social relevance of higher education; globalization; biopiracy; the culture of evaluation; the need for new leadership; political actions, and the Rio+20 conference results.

O objetivo central deste estudo foi analisar a migração de japoneses para a Amazônia peruana e sua consolidação em Puerto Maldonado (Madre de Dios). Três foram as principais causas desse processo: 1) Uma política contínua em prol da imigração japonesa para o Peru durante as primeiras décadas do século XX voltada para prover mão-de-obra nas fazendas de cana-de-açúcar e algodão da costa; 2) Envolvimento dos imigrantes japoneses em atividades econômicas demandadas durante a expansão da exploração da borracha na Amazônia peruana; e 3) Fortalecimento dessas atividades após a queda da economia da borracha para garantir o fornecimento de produtos necessários à população remanescente, inclusive, substituindo produtos não mais importados ou fornecidos por grandes empresas. A Amazônia peruana tornou-se cada vez mais atrativa para os imigrantes japoneses inconformados com as más condições de trabalho nas fazendas da costa, engrossando assim a migração para essa região. A própria existência de uma comunidade mais ou menos organizada que serviu de suporte na Amazônia peruana permitiu fortalecer a vinda de mais migrantes. Em Puerto Maldonado, os japoneses se dedicaram à produção de hortifrutigranjeiros e outros produtos agrícolas para suprir o mercado local, estabeleceram pequenos comércios, e forneciam alguns serviços especializados