A light responsive semiconductor includes a second conductivity type semiconductor substrate, a photoelectric conversion layer comprising semiconductor layers having a pn junction, which is disposed on the second conductivity type semiconductor substrate, a buffer layer comprising a second conductivity type semiconductor layer having a larger energy band gap than that of the photoelectric conversion layer. The element further includes a light reflection layer comprising a semiconductor layer which is disposed between the second conductivity type semiconductor substrate and the buffer layer. Alternatively, a light reflection layer which is a buffer layer is disposed between a photoelectric conversion layer and a semiconductor substrate.