A semi-conducting structure, configured to receive an electromagnetic radiation and to transform the electromagnetic radiation into an electric signal, including: a first zone and a second zone of a same conductivity type and of same elements; a barrier zone, provided between the first and second zones, for acting as a barrier to majority carriers of the first and second zones on a barrier thickness, the barrier zone having its lowest bandgap energy defining a barrier proportion; and a first interface zone configured to interface the first zone and the barrier zone on a first interface thickness, the first interface zone including a composition of elements which is varied from a proportion corresponding to that of the first material to the barrier proportion, the first interface thickness being at least equal to half the barrier thickness.