The present application provides a semiconductor device and an electronic device. In the semiconductor device, a metal layer is provided on the side of the active layer facing the buffer layer, and the metal layer includes at least one metal block, so that the metal block is in direct contact with at least part of the active layer, then when the active layer is converted from amorphous silicon to polycrystalline silicon, due to the catalytic effect of the metal block, the size of the crystal grains in the polycrystalline silicon becomes larger, which reduces the crystal grain boundaries in the polycrystalline silicon and improves the mobility of the semiconductor device.