Abstract
It is shown that the current collected by a p-n junction in presence of a unit point generation of carriers at a point P is the same (apart from the dimensions) as the excess minority-carrier density at P due to a unit density of carriers at the junction edge. Use of this reciprocity relation may simplify the calculation of beam induced currents in semiconductor devices. The practical meaning of this property is illustrated in the case of a light-emitting diode containing defects.