Breakdown-avalanche photon sensors array, which is implemented in CMOS technology, wherein the breakdown-avalanche photon sensors array has single photon sensitivity, comprising: a semiconductor substrate; and an epitaxial layer, which is located above the semiconductor substrate; and a breakdown-avalanche photon sensor, which is located within the epitaxial layer, wherein the breakdown-avalanche photon sensor comprises: a guard ring; a lower layer and an upper layer within epitaxial layer, which form a sensitive breakdown-avalanche pn-junction, wherein the guard ring is located within the epitaxial layer at the edges of the sensitive breakdown-avalanche pn-junction; wherein the guard ring comprises less doping than the upper layer and the guard ring is configured for suppression of a breakdown-avalanche process at edges of the breakdown-avalanche photon sensor due to a weaker electric field at or near a guard ring area compared to an electric field within a central region of the sensitive breakdown-avalanche pn-junction; and a quenching element, which is electrically connected to an area of the pn-junction of the breakdown-avalanche photon sensor, wherein the quenching element is configured for quenching the breakdown-avalanche photon sensor after detection of a photon. a semiconductor substrate; and an epitaxial layer, which is located above the semiconductor substrate; and a breakdown-avalanche photon sensor, which is located within the epitaxial layer, wherein the breakdown-avalanche photon sensor comprises: a guard ring; a lower layer and an upper layer within epitaxial layer, which form a sensitive breakdown-avalanche pn-junction, wherein the guard ring is located within the epitaxial layer at the edges of the sensitive breakdown-avalanche pn-junction; wherein the guard ring comprises less doping than the upper layer and the guard ring is configured for suppression of a breakdown-avalanche process at edges of the breakdown-avalanche photon sensor due to a weaker electric field at or near a guard ring area compared to an electric field within a central region of the sensitive breakdown-avalanche pn-junction; and a quenching element, which is electrically connected to an area of the pn-junction of the breakdown-avalanche photon sensor, wherein the quenching element is configured for quenching the breakdown-avalanche photon sensor after detection of a photon. a guard ring; a lower layer and an upper layer within epitaxial layer, which form a sensitive breakdown-avalanche pn-junction, wherein the guard ring is located within the epitaxial layer at the edges of the sensitive breakdown-avalanche pn-junction; wherein the guard ring comprises less doping than the upper layer and the guard ring is configured for suppression of a breakdown-avalanche process at edges of the breakdown-avalanche photon sensor due to a weaker electric field at or near a guard ring area compared to an electric field within a central region of the sensitive breakdown-avalanche pn-junction; and a quenching element, which is electrically connected to an area of the pn-junction of the breakdown-avalanche photon sensor, wherein the quenching element is configured for quenching the breakdown-avalanche photon sensor after detection of a photon.