Societe Francaise De Detecteurs Infrarouges-Sofradir

Lynred

Alexandre Kerlain

Laurent Rubaldo

Alexandru Nedelcu

Nicolas Pere-Laperne

Nicolas Pere Laperne

Paul Fougeres

Vincent Destefanis

A substrate to fabricate a photodiode structure has a top layer made from cadmium-doped semiconductor material. A first HgCdTe-base layer is formed by liquid phase epitaxy from the top layer with a bath containing an n-type electrically active dopant to electrically dope the first layer. The cadmium diffuses from the top layer to the first layer to form a decreasing cadmium concentration gradient from the interface with the top layer in a direction away from the interface. The cadmium concentration gradient causes a decreasing band gap width gradient in the first layer from the interface and causes an n-type dopant concentration gradient in the first layer from the interface.

Method for fabricating a photodiode structure and photodiode structure

The photodetector includes a photon absorbing region formed by a first semiconductor material having a first bandgap energy value. It also includes a blocking region formed by at least second and third semiconductor materials configured to prevent the majority charge carriers from passing between the photon absorbing region and a contact region, the second semiconductor material presenting a second bandgap energy value higher than the first bandgap energy value to form a quantum well with the third semiconductor material. The blocking region is doped.

Photodetector with reduced dark current

Growing community of inventors

Grenoble, France

Alexandre Kerlain