Photodetector designing method for photodetector having photoelectric conversion layer mostly composed of amorphous selenium and layer thickness designing method thereof, photodetector using the photoelectric conversion layer and photodetector manufacturing method thereof, and storage medium

A photodetector comprising, in order from a light incidence side:

• a first substrate including a transparent electrode;
• a photoelectric conversion layer having a superlattice structure mostly composed of amorphous selenium and having a layer thickness obtained by multiplying a thickness per one layer of the superlattice structure by the number of layers NSL of the superlattice structure approximate to a multiplication factor M representing an amplification gain generated in a process of tunneling in the superlattice structure the multiplication factor M being calculated by the following equation:
• M
• =
• I
• C
• -
• I
• D
• q
• ⁢
• N
• 0
• ⁢
• 0
• wherein Ic is a collector current, ID is an amount of dark current to be allowed by the photodetector, q is a basic electronic charge, and N00 is the number of photons serving as carriers in the tunneling;
• and
• a second substrate of a substrate type which is suitable for a requirement for a wavelength to be detected by the photoelectric conversion layer and on which the photoelectric conversion layer is laminated,
• wherein only the photoelectric conversion layer determines the amount of dark current ID.

A photodetector comprising, in order from a light incidence side:

• a first substrate including a transparent electrode,
• an anode layer that functions as a photoelectric conversion layer having a superlattice structure mostly composed of amorphous selenium and having a layer thickness obtained by multiplying a thickness per one layer of the superlattice structure by the number of layers NSL of the superlattice structure approximate to a multiplication factor M representing an amplification gain generated in a process of tunneling in the superlattice structure the multiplication factor M being calculated by the following equation:
• M
• =
• I
• C
• -
• I
• D
• q
• ⁢
• N
• 0
• ⁢
• 0
• wherein Ic is a collector current, ID is an amount of dark current to be allowed by the photodetector q is a basic electronic charge, and N00 is the number of photons serving as carriers in the tunneling;
• a vacuum gap;
• and
• a cathode layer,
• wherein only the anode layer determines the amount of dark current ID.