A lightweight, silicon-based solar cell that can be installed on curved surfaces such as fabrics could be used for a broad range of applications. A paper online this week in Nature Materials (http://dx.doi.org/10.1038/nmat2287) describes the new device, one of the most efficient flexible solar cells designed so far.
 
In earlier designs, flexible solar cells were either made from inefficient organic materials or used thick inorganic films, for example of silicon, which had limited flexibility. US-based researchers make use of a transfer printing approach, where ultrathin, and therefore highly pliable, silicon components are lifted from a silicon wafer and transferred onto a polymer substrate, to make centimetre-scale solar cells. This approach combines the benefits of flexibility with the good light-absorption of silicon. The transfer printing technique itself is versatile and could be applied to a broad range of materials and device designs.
 
 
Abstract of this article:
 
 

The high natural abundance of silicon, together with its excellent reliability and good efficiency in solar cells, suggest its continued use in production of solar energy, on massive scales, for the foreseeable future. Although organics, nanocrystals, nanowires and other new materials hold significant promise, many opportunities continue to exist for research into unconventional means of exploiting silicon in advanced photovoltaic systems.Here,we describemodules that use large-scale arrays of silicon solar microcells created from bulk wafers and integrated in diverse spatial layouts on foreign substrates by transfer printing. The resulting devices can offer useful features, including high degrees of mechanical flexibility, user-definable transparency and ultrathin-form-factor microconcentrator designs. Detailed studies of the processes for creating and manipulating such microcells, together with theoretical and experimental investigations of the electrical, mechanical and optical characteristics of several types of module that incorporate them, illuminate the key aspects.