A radiation detector , comprising: a read-out sensor array , a first scintillator structure, a second scintillator structure and a coating , wherein the read-out sensor array comprises a plurality of light-sensitive sensor pixels; wherein the first scintillator structure comprises a plurality of first scintillator pixels separated by gaps ; wherein the second scintillator structure is optically coupled to the first scintillator structure; wherein the first scintillator structure and the second scintillator structure are arranged between the coating and the read-out sensor array ; wherein the second scintillator structure at least partially overlaps the gaps between the first scintillator pixels of the first scintillator structure; wherein the second scintillator structure comprises a plurality of second scintillator pixels separated by gaps; wherein at least one second scintillator pixel at least partially overlaps a gap between the first scintillator pixels ; characterised in that the first scintillator structure comprises ceramic scintillator material; wherein the second scintillator structure comprises particle-in-binder scintillator material; and wherein the at least one second scintillator pixel comprises a slanted surface section, which is inclined relative to a layer formed by the first scintillator structure to reflect light from inside the at least one second scintillator pixel towards a first scintillator pixel , which is optically coupled to the at least one second scintillator pixel ; or wherein the at least one second scintillator pixel is tilted relative to the layer formed by the first scintillator structure to increase a gap between the at least one second scintillator pixel and a first scintillator pixel , which is not optically coupled to the at least one second scintillator pixel . a read-out sensor array , a first scintillator structure, a second scintillator structure and a coating , wherein the read-out sensor array comprises a plurality of light-sensitive sensor pixels; wherein the first scintillator structure comprises a plurality of first scintillator pixels separated by gaps ; wherein the second scintillator structure is optically coupled to the first scintillator structure; wherein the first scintillator structure and the second scintillator structure are arranged between the coating and the read-out sensor array ; wherein the second scintillator structure at least partially overlaps the gaps between the first scintillator pixels of the first scintillator structure; wherein the second scintillator structure comprises a plurality of second scintillator pixels separated by gaps; wherein at least one second scintillator pixel at least partially overlaps a gap between the first scintillator pixels ; characterised in that the first scintillator structure comprises ceramic scintillator material; wherein the second scintillator structure comprises particle-in-binder scintillator material; and wherein the at least one second scintillator pixel comprises a slanted surface section, which is inclined relative to a layer formed by the first scintillator structure to reflect light from inside the at least one second scintillator pixel towards a first scintillator pixel , which is optically coupled to the at least one second scintillator pixel ; or wherein the at least one second scintillator pixel is tilted relative to the layer formed by the first scintillator structure to increase a gap between the at least one second scintillator pixel and a first scintillator pixel , which is not optically coupled to the at least one second scintillator pixel . <EOS>