Ultrathin nanostructured c-Si solar cells by low temperature and scalable processes

We report on the fabrication and characterization of both flat and patterned c-Si solar cells on glass. We use epitaxial layers grown by plasma enhanced chemical vapor deposition at low temperature (T<;200°C), and anodic bonding on glass substrate. Inverted nanopyramids are fabricated by nanoimprint lithography and wet etching in alkaline solution. With 3μm-thick c-Si layers, the performances achieved with planar solar cells are Jsc = 18.3mA/cm2 and η = 6.1%. With an additional nanopyramid array on the front side of the cell, an improved short-circuit current of 25.3mA/cm2 is obtained. We present the latest experimental results and discuss the path to be followed to achieve low cost, ultrathin c-Si solar cells with a 15% targeted efficiency.