Photodetector comprising a stack of vertically adjacent layers

A photodetector comprising:

• a stack of superimposed layers comprising, successively in a stacking direction:
• a first layer forming a substrate made of a first semiconductor material,
• a second layer forming a photo-absorbent layer made of a second semiconductor material having a second gap,
• a third layer forming a barrier layer made of a third semiconductor material, and
• a fourth layer forming a window layer made of a fourth semiconductor material, the window layer being a barrier layer enabling reduction of parasitic effects of surface recombination of electrostatic shielding associated with electrical doping of the fourth layer,
• the first material, the third material, and the fourth material each having a gap greater than the second gap,
• the fourth material being n-doped or undoped and the third material being undoped or weakly p-doped when the second material is n-doped, and
• the fourth material being p-doped or undoped and the third material being undoped or slightly n-doped when the second material is p-doped,
• wherein a doping rate of the fourth material is between 1015 cm−3 and 1017 cm−3.