| abstract |
A photodiode and the like capable of preventing the responsivity on the short wavelength side from deteriorating while totally improving the responsivity in a type II MQW structure, is provided. The photodiode is formed on a group III-V compound semiconductor substrate 1 , and includes a pixel P. The photodiode includes an absorption layer 3 of a type II MQW structure, which is located on the substrate 1 . The MQW structure includes fifty or more pairs of two different types of group III-V compound semiconductor layers 3 a and 3 b . The thickness of one of the two different types of group III-V compound semiconductor layers, which layer 3 a has a higher potential of a valence band, is thinner than the thickness of the other layer 3 b. |