Developing an advanced module for back-contact solar cells

This paper proposes a novel concept for integrating ultrathin solar cells into modules. It is conceived as a method for fabricating solar panels starting from back-contact crystalline silicon solar cells. However, compared to the current state of the art in module manufacturing for back-contact solar cells, this novel concept aims at improvements in performance, reliability, and cost through the use of an alternative encapsulant, namely silicones as opposed to ethylene vinyl acetate, an alternative deposition technology, being wet coating as opposed to dry lamination; and alternative module-level metallization techniques, as opposed to cell-level tabbing-stringing or conductive foil interconnects. The process flow is proposed, and the materials and fabrication technologies are discussed. As the durability of the module, translated into the module's lifetime, is very important in the targeted application, namely solar cell modules, modeling and reliability testing results and considerations are presented to illustrate how the experimental development process may be guided by experience and theoretical derivations. Finally, feasibility is demonstrated in some first proofs of the concept, and an outlook is given pointing out the direction for further research

Studies of implanted boron emitters for solar cell applications

International audienceB implanted emitters are investigated in the back junction cell configuration and their material properties are tested in double side implanted Si wafers. B has been implanted at 5 keV at various dose conditions varying from 1 Â 10 14 up to 3 Â 10 15 at./cm 2 and activated at 10008C for 10 min. N-type 8 Â 8 cm 2 mono-crystalline cells are fabricated and measured. Both fill factor and efficiency increase for high-B doses. However, at 10 15 at./cm 2 B dose the V oc drops, which is in agreement with lifetime degradation in the wafer. Defect evolution simulations of B n I m clusters formation is correlated with lifetime degradation

Development of solar cells on RST-ribbons

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Gettering effects and FG annealing on thin RST ribbon silicon solar cells

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Performance of a new type of module based on back-contact solar cells

Imec has developed a new technology to integrate and interconnect back-contact solar cells into modules, based on embedding cells in silicone on top of a glass substrate. This technology aims at an improved optical performance and reliability (through the use of silicones and low-temperature metallization). One of the additional advantages is that the technology is suitable for integrating very thin cells into modules: whereas standalone interconnection of such fragile thin cells, e. g. tabbing and stringing, would significantly lower the throughput yield due to breakage, the cells are better protected if they are embedded inside silicone. The paper will first elaborate on the process flow, the background and motivation, advantages, drawbacks and limitations, and technical aspects of the developed technology. Then it will present the results of the measurements on the performance of functional solar cells processed into modules using this technology, discussing losses and loss mechanisms. Then, the approach towards determining the reliability of the module will be presented, indicating how imec aims at building up an ageing model, and elaborating the results on the failure mode and effect analysis, modeling, characterization and reliability testing