50 μm thin solar cells with 17.0% efficiency

Monocrystalline silicon solar cells with thicknesses below 50 μm manufactured by the transfer layer process at ipe reach efficiencies as high as 17.0%. We present a thin film solar cell, which is not attached to a glass superstrate, opening new process opportunities, as for example the usage of flexible superstrates. We show a free-standing 47 μm thin solar cell with a record conversion efficiency η=17.0%.