Infrared photodetector formed by array of semiconductor elements shaped to have increased electron diffusion area

A photodetector comprising:

• a substrate made of a first semiconductor type and having a surface;
• and
• a plurality of independent diffusion regions formed in the surface of said substrate and made of a second semiconductor type which is opposite to the first semiconductor type so that a pn junction is formed between the substrate and each diffusion region,
• discrete photosensitive areas being formed by each of said diffusion regions and blind areas being formed between adjacent ones of said photosensitive areas when a bias voltage is applied across each pn junction,
• each of said photosensitive areas having the same area,
• at least predetermined ones of said diffusion regions having a main part and at least one auxiliary part which is independent of the main part on the surface of said substrate but electrically coupled to the main part,
• said auxiliary part being provided in a region on the surface of said substrate towards a corresponding one of said blind areas relative to the main part, so that the blind area is reduced by a part of the photosensitive area formed by the auxiliary part of the diffusion region;
• each said diffusion region forms a photosensitive area when a bias voltage is applied across a corresponding pn junction,
• blind areas are formed between adjacent photosensitive areas, and
• the photosensitive areas are arranged in a substantially contiguous manner so that the adjacent photosensitive areas are in contact with or very close to each other.