Patent attributes
A photodiode is provided which can operate at a high rate and is suitable for optical communications. The photodiode with a pin-type configuration of an end surface incidence type includes a first photodiode unit having a first n-type blocking layer, a first light-absorbing layer constituted by an intrinsic semiconductor, and a first p-type blocking layer on a semiinsulating substrate; a second photodiode unit having layers of the same configuration formed thereon; a contact layer; a first electrode; and a second electrode, wherein the thickness of each light-absorbing layer is half that in a conventional monolayer photodiode. As a result, the maximum travel time of the carriers (electrons and holes) in each photodiode unit is reduced by half and the photodiode can operate at a rate higher than that of the conventional photodiode.
