Photodetector and control method of photodetector

A photodetector comprising a plurality of photoelectric conversion devices, wherein each of the photoelectric conversion devices comprises:

• a cathode electrode;
• an anode electrode arranged around the cathode electrode;
• an electron multiplication region comprising a first region of a first conductivity type in contact with a second region of a second conductivity type;
• a voltage transfer region of the first conductivity type arranged around the cathode electrode and configured to transfer a voltage of the anode electrode to the first region of the electron multiplication region;
• a gate electrode arranged around the cathode electrode and facing the voltage transfer region with an insulating film arranged therebetween;
• and
• a gate voltage controller configured to adjust a gate voltage applied to the gate electrode, based on one or more of a detected temperature of the photoelectric conversion device, a dark count rate (DCR) of the photoelectric conversion device, and an amount of light around the photoelectric conversion device,
• wherein a degree of voltage transfer from the voltage transfer region to the first region is adjustable based on the gate voltage applied to the gate electrode.

A control method of a photodetector comprising a plurality of photoelectric conversion devices, wherein each of the photoelectric conversion device comprises:

• a cathode electrode;
• an anode electrode arranged around the cathode electrode;
• an electron multiplication region comprising a first region of a first conductivity type in contact with a second region of a second conductivity type;
• a voltage transfer region of the first conductivity type arranged around the cathode electrode and configured to transfer a voltage of the anode electrode to the first region of the electron multiplication region;
• and
• a gate electrode arranged around the cathode electrode and facing the voltage transfer region with an insulating film arranged therebetween,
• wherein a degree of voltage transfer from the voltage transfer region to the first region is adjusted by a gate voltage applied to the gate electrode, the control method comprising:
• (a) detecting:
• a temperature of a first photoelectric conversion device of the plurality of photoelectric conversion devices,
• a dark count rate (DCR) of the first photoelectric conversion device, and/or
• an amount of light around the first photoelectric conversion device;
• and
• (b) adjusting the gate voltage, based on:
• the detected temperature of the first photoelectric conversion device,
• the detected DCR of the first photoelectric transfer device, and/or
• the detected amount of light around the first photoelectric conversion device.