Ultrathin nanostructured c-Si solar cells by low temperature and scalable processes
Résumé
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 degrees C), and anodic bonding on glass substrate. Inverted nanopyramids are fabricated by nanoimprint lithography and wet etching in alkaline solution. With 3 mu m-thick c-Si layers, the performances achieved with planar solar cells are Jsc = 18.3mA/cm(2) and eta = 6.1%. With an additional nanopyramid array on the front side of the cell, an improved short-circuit current of 25.3mA/cm(2) 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.