Architecture for InGaAs/GaAsSb superlattices on an InP substrate

A device (D1) for detecting infrared radiation comprising at least one pixel (Pxl), a pixel comprising a planar absorbing structure (SPA), said planar absorbing structure (SPA) comprising:

• a first superlattice (SR1, SR2) comprising a stack along a stacking direction (Z) of an elementary group (G1, G2) of semiconductor layers, the semiconductor layers of said elementary group (G1, G2) each being arranged in a crystalline lattice structure of unit cells;
• said elementary group comprising:
• a first layer (C1) made of a first semiconductor (SC1) having
• a first bandgap (Eg1),
• and a first conduction-band minimum (Ec1);
• at least a second layer (C2) made of a second semiconductor (SC2) having
• a second bandgap (Eg2),
• and a second conduction-band minimum (Ec2) strictly lower than the first conduction-band minimum (Ec1);
• a third layer (C3) made of a third semiconductor (SC3) having
• a third bandgap (Eg3) narrower than the first and second bandgaps (Eg1, Eg2),
• and a third conduction-band minimum (Ec3) strictly lower than the second conduction-band minimum (Ec2);
• the elementary group (G1, G2) being produced:
• in a first stacking configuration in the following order:
• the second layer (C2), the third layer (C3), the second layer (C2), then the first layer (C1);
• or in a second stacking configuration such that the third layer (C3) is confined between the first and second layers (C1, C2):
• wherein the first semiconductor (SC1) further has a first valence-band maximum (Ev1) and the second semiconductor (SC2) further has a second valence-band maximum (Ev2) strictly lower than the first valence-band maximum (Ev1).