The present invention relates to a solar cell comprising a heterojunction photoelectric device comprising, a front electrode layer, a back electrode layer comprising a metallic contact layer (300), a light-absorbing silicon layer (1 ) arranged between said front electrode and said back electrode layers and a doped silicon-based layer (6) arranged between said light-absorbing silicon layer (1 ) and said back electrode layer, characterized in that said heterojunction photoelectric device further comprises a wide band gap material layer (10) having an electronic band gap greater than 1.4eV, said wide band gap material layer being applied on a surface of the light- absorbing silicon layer (1 ) between said light-absorbing silicon layer and said doped silicon-based layer (6). The present heterojunction layer or stack of layers is compatible with thermal annealing and firing processes at T above 600 °C.