An aqueous dispersion comprising a binder or a surfactant, a substantially light-insensitive and substantially water-insoluble organic silver salt and a photosensitive silver halide, wherein the aqueous emulsion further comprises a sensitization agent selected from the group consisting of: tin(II) bromide, aminoiminomethane sulfinic acid, water-soluble salts of H3PO3, water-soluble salts of H3PO2, water-soluble SO32null salts and water-soluble HSO3null salts; and production process for therefor and a photothermographic recording material comprising a support and a photo-addressable thermally developable element, the photo-addressable thermally developable element fulfilling two requirements: (i) the photo-addressable thermally developable element contains a substantially light-insensitive and substantially water-insoluble organic silver salt, a reducing agent for the substantially light-insensitive and substantially water-insoluble organic silver salt and in thermal working relationship therewith, a photosensitive silver halide and a binder; and (ii) the photo-addressable thermally developable element comprises a layer obtainable by coating the above-mentioned aqueous dispersion onto the support.