Abstract: A single photon avalanche diode (SPAD) includes a PN junction in a semiconductor well doped with a first type of dopant. The PN junction is formed between a first region doped with the first type of dopant and a second region doped with a second type of dopant opposite to the first type of dopant. The first doped region is shaped so as to incorporate local variations in concentration of dopants that are configured, in response to a voltage between the second doped region and the semiconductor well that is greater than or equal to a level of a breakdown voltage of the PN junction, to generate a monotonic variation in the electrostatic potential between the first doped region and the semiconductor well.

Abstract: An avalanche photodiode includes a stack of layers. The stack of layers includes an avalanche diode (of PN or PIN type) and a layer having quantum dots located therein. The stack of layers further includes: a charge extraction layer over the layer which includes quantum dots; a transparent conducting layer over the charge extraction layer; and an insulating layer over the transparent conducting layer. The quantum dots includes ligands formed by molecules of dopants.

Abstract: A single photon avalanche diode (SPAD) includes a PN junction in a semiconductor well doped with a first type of dopant. The PN junction is formed between a first region doped with the first type of dopant and a second region doped with a second type of dopant opposite to the first type of dopant. The first doped region is shaped so as to incorporate local variations in concentration of dopants that are configured, in response to a voltage between the second doped region and the semiconductor well that is greater than or equal to a level of a breakdown voltage of the PN junction, to generate a monotonic variation in the electrostatic potential between the first doped region and the semiconductor well.