Abstract: A photo-detecting device includes a first semiconductor layer with a first dopant, a light-absorbing layer, a second semiconductor layer, and a semiconductor contact layer. The second semiconductor layer is located on the first semiconductor layer and has a first region and a second region, the light absorbing layer is located between the first semiconductor layer and the second semiconductor layer and has a third region and a fourth region, the semiconductor contact layer contacts the first region. The first region includes a second dopant and a third dopant, the second region includes second dopant, and the third region includes third dopant. The semiconductor contact layer has a first thickness greater than 50 ? and smaller than 1000 ?.

Abstract: A photo-detecting device includes a first semiconductor layer with a first dopant, a light-absorbing layer, a second semiconductor layer, and a semiconductor contact layer. The second semiconductor layer is located on the first semiconductor layer and has a first region and a second region, the light absorbing layer is located between the first semiconductor layer and the second semiconductor layer and has a third region and a fourth region, the semiconductor contact layer contacts the first region. The first region includes a second dopant and a third dopant, the second region includes second dopant, and the third region includes third dopant. The semiconductor contact layer has a first thickness greater than 50 ? and smaller than 1000 ?.

Abstract: A photodiode includes a substrate having a lateral side having an inclined light incidence surface that forms an angle of 45 or 60 degrees with respect to a normal of the substrate; and an epitaxial layer disposed on the substrate. A method for manufacturing a photodiode is provided, including: providing a substrate; forming an epitaxial layer on the substrate; and making a lateral side of the substrate an inclined light incidence surface that forms an angle of 45 or 60 degrees with respect to a normal of the substrate. Another method is also provided, including: providing a substrate; forming an etch stop layer on the substrate; forming an epitaxial layer on the etch stop layer; and applying an agent to etch a lateral side of the substrate to form an inclined light incidence surface having an angle of 45 or 60 degrees with respect to a normal of the substrate.