摘要 |
A substrate consisting of a compound semiconductor crystal, a buffer layer, a graded layer, a light-absorbing layer having a lattice constant smaller than that of the uppermost mixed crystal sublayer of the graded layer, a p-type conductive layer, another p-type conductive layer, and a capping layer formed on the surface of the light-absorbing layer next to the p-type conductive layer and having almost the same lattice constant as that of the uppermost layer of the graded layer are stacked. An electrode is connected to the substrate, and another electrode is connected to the conductive layer. A tensile force is applied to the light-absorbing layer from the uppermost mixed crystal sublayer of the graded layer, the capping layer, and the conductive layer, thereby suppressing a dark current.
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