Photodiode having a p-n junction with varying expansion of the space charge zone due to application of a variable voltage

A photodiode array comprising:

• a plurality of photodiodes, each photodiode comprising
• a semiconductor material having a p-n junction, the p-n junction being located between a first doping region of a first doping type and a second doping region of a second doping type, the second doping region comprising a highly doped layer and a lightly doped layer, the highly doped layer being arranged adjacent to the first doping region and the lightly doped layer being arranged adjacent to the highly doped layer,
• a voltage source, the voltage source being connected to the first doping region and the lightly doped layer of the second doping region via contacts, the voltage source configured to apply a variable voltage between the first doping region and the lightly doped layer of the second doping region in order to vary the expansion of a space charge zone of the p-n junction from a region of the junction between the first doping region and the highly doped layer of the second doping region to a region enlarged from the first doping region via the highly doped layer of the second doping region into the lightly doped layer of the second doping region, and
• a current detection circuit, the current detection circuit being connected to the first doping region and the lightly doped layer of the second doping region via the contacts in order to detect a current flow between the first doping region and the second doping region,
• wherein laterally arranged isolation trenches are provided between the individual photodiodes.

A method of operating a photodiode comprising a semiconductor material having a p-n junction, the p-n junction being located between a first doping region of a first doping type and a second doping region of a second doping type, the second doping region comprising a highly doped layer and a lightly doped layer, the highly doped layer being arranged adjacent to the first doping region and the lightly doped layer being arranged adjacent to the highly doped layer,

• a voltage source, the voltage source being connected to the first doping region and the lightly doped layer of the second doping region via contacts, the voltage source configured to apply a variable voltage between the first doping region and the lightly doped layer of the second doping region in order to vary the expansion of a space charge zone of the p-n junction from a region of the junction between the first doping region and the highly doped layer of the second doping region to a region enlarged from the first doping region via the highly doped layer of the second doping region into the lightly doped layer of the second doping region, and
• a current detection circuit, the current detection circuit being connected to the first doping region and the lightly doped layer of the second doping region via the contacts in order to detect a current flow between the first doping region and the second doping region, the method comprising:
• applying a voltage by the voltage source between the first doping region and the lightly doped layer of the second doping region, wherein the voltage applied between the first doping region and the lightly doped layer of the second doping region is changed in steps in order to vary the expansion of a space charge zone of the p-n junction;
• and, in each voltage step,
• gathering charge carriers generated by an electromagnetic radiation in the space charge zone of the p-n junction between the first doping region and the second doping region by the current detection circuit.

A device including a photodiode comprising:

• a semiconductor material having a p-n junction, the p-n junction being located between a first doping region of a first doping type and a second doping region of a second doping type, the second doping region comprising a highly doped layer and a lightly doped layer, the highly doped layer being arranged adjacent to the first doping region and the lightly doped layer being arranged adjacent to the highly doped layer;
• a voltage source, the voltage source being connected to the first doping region and the lightly doped layer of the second doping region via contacts, the voltage source configured to apply a variable voltage between the first doping region and the lightly doped layer of the second doping region in order to vary the expansion of a space charge zone of the p-n junction from a region of the junction between the first doping region and the highly doped layer of the second doping region to a region enlarged from the first doping region via the highly doped layer of the second doping region into the lightly doped layer of the second doping region;
• and
• a current detection circuit electrically coupled to the semiconductor material.