imaging systems, [3][4][5][6][7] nanophotonics, [8] light generation and communication, [1] energy harvesting, [9][10][11] and advanced textiles. [12,13] To functionalize optical fibers, a first strategy relies on wafer-based techniques [8] and modified deposition [14,15] to integrate functional materials at the tip or within a few tens of centimeters of microstructured silica fibers. An alternative approach exploits the well-established thermal drawing of macroscopic preforms that integrate the desired multimaterial architecture. [1] This has the advantage of simplicity and scalability, since the fiber pulling step results in tens of kilometers of fibers that have the same crosssectional structure as the initial preform. Thus far however, realizing high-quality semiconducting materials that can act as high-performance photodetectors using the thermal drawing process remains a challenge. A recent strategy consists in the thermal drawing within silica fibers of high melting point materials such as silicon, [16] germanium, [17] or various compounds. [18] The melting and solidification during drawing result however in semiconductors with a highly polycrystalline microstructure, requiring local postdrawing annealing or laserbased steps to engineer a desired microstructure. [15,18,19] It is also difficult to integrate electrodes in contact with the semiconducting domains and despite an ingenious and promising method, no device with good optoelectronic properties has been shown. [17] The alternative strategy relies on exploiting the polymer fiber platform. It has several advantages compared to its silica counterpart, including low-temperature processing, robust mechanical properties, simple integration of electrodes, and the ability to impart fibers with complex architectures and multiple functionalities. [1] Thus far however, the postdrawing crystallization schemes applied to semiconducting chalcogenide glasses have resulted in poor control over the phase, grain size, and orientation, impairing device performance. [5,20] A powerful approach to control the microstructure and enhance optoelectronic performance is via the growth of welloriented semiconducting nanowires. This approach has not been exploited in the frame of fiber-integrated devices since conventional fabrication procedures of semiconducting nanowires are complex and only adapted to specific substrates seemingly incompatible with the thermal drawing process and the fiber materials and geometry. [8,21] Here, we demonstrate for the first time the robust and scalable integration of high-qualityThe recent ability to integrate semiconductor-based optoelectronic functionalities within thin fibers is opening intriguing opportunities for flexible electronics and advanced textiles. The scalable integration of high-quality semiconducting devices within functional fibers however remains a challenge. It is difficult with current strategies to combine high light absorption, good microstructure and efficient electrical contact. The growth of semiconducting nanowires is ...

International audienceSb2S3 is widely considered to be an attractive photovoltaic material based on abundant, nontoxic elements. However, the maximum efficiency reported for solar cells based on this semiconductor does not exceed 6.5%. We have measured light intensity-dependent J-V curves, transient microwave photoconductivity, steady-state photocurrent grating, modulated photocurrent, and photoconductivity on Sb2S3-based samples. All techniques converge toward the same observation: the main recombination route controlling the density of charge carriers in the absorber is of an order greater than one and appears to stem from an exponentially decaying density of tail states within the conduction band of the material. This conclusion has direct and drastic implications for the performance of Sb2S3-based solar cells

The energy conversion chain in a photovoltaic water pumping system was modelled.  Water collection by the inhabitants was included as a model input.  The model was validated by using data acquired on a system in rural Africa.  The accuracy of the model is higher than 95 % when using local climatic data.  Accuracy drops of 1 to 3 % when replacing local climatic data by satellite ones.