One embodiment provides a method, including: receiving a photon interaction occurring within a photon detector pixel array, wherein the photon detector pixel array comprises a plurality of pixels; determining a photoelectron cloud generated from the photon interaction, wherein the photon detector pixel array comprises an electric field, wherein an electrostatic repulsive force disperses a photon to the photoelectron cloud; identifying a subset of the plurality of pixels associated with the photon interaction, wherein each of the subset of the plurality of pixels corresponds to pixels activated by the photo electron cloud, wherein the subset of the plurality of pixels comprise a central pixel and a plurality of neighboring pixels, wherein the central pixel comprises the pixel having the highest amplitude response to the photon interaction; and determining, from the photoelectron cloud, a characteristic of the photon interaction, wherein the characteristic comprises at least one of: time, position, and energy of the interaction. Other aspects are described and claimed.