At the 39th Photovoltaic Specialist Conference in Tampa, Florida, there were two important and interesting topics which were of particular interest to me.
The first one was covered by Harry A. Atwater, California Institute of Technology (http://daedalus.caltech.edu/research/thinfilmpv.php) “Full Spectrum High Efficiency Photovoltaics” . He was discussing a new concept: splitting the incident solar spectrum into its constituent wavelengths, guiding these different wavelengths into solar cells with different bandgaps, then absorbing them (shown in Figure 1). In theory, the efficiency of such thin film solar cell system can range from around 30% to over 50%. One way of splitting incident light is to use specially engineered nanostructures printed on the surface of a solar cell or planar holographic elements. In the latter case, the solar spectrum is split four ways via a stack of three sinusoidal volume Bragg gratings, where three bands are diffracted at different angles and the 4
View original post 332 more words