Solar cell

A solar cell comprising a semiconductor layer (1), a collecting layer (6) for collecting free charge carriers from the semiconductor layer (1) and a buffer layer (3) which is arranged between the semiconductor layer (1) and the collecting layer (6), which buffer layer (3) is designed as a tunnel contact (31) between the semiconductor layer (1) and the collecting layer (6) is characterised in that the buffer layer (3) essentially comprises a material with a surface charge density of at least 1012 cm-2, preferably of at least 5x1012 cm- 2