Semiconductor device for receiving light

摘要

A semiconductor device for receiving light includes a first semiconductor layer having a first conductivity type; the device further includes a second semiconductor layer having the first conductivity type, contacting the first semiconductor layer, having a forbidden bandwidth larger than that of the first semiconductor layer and distributed so that the forbidden bandwidth has a maximum value at an intermediate position in the vertical direction and of the second semiconductor layer. The semiconductor device further includes a third semiconductor region having a second conductivity type opposite the first conductivity type, contacting the second semiconductor layer and having a forbidden bandwidth smaller than that of the third contact end portion between the semiconductor region and the second semiconductor layer and larger than that of the first semiconductor layer. The third semiconductor region having the second conductivity type acts as a window layer through which incident light is transmitted.