An X-ray detector (10) for a phase contrast imaging system (100) and a phase contrast imaging system (100) with such detector (10) are provided. The X-ray detector (10) comprises a scintillation device (12) and a photodetector (14) with a plurality of photosensitive pixels (15) optically coupled to the scintillation device (12), wherein the X-ray detector (10) comprises a primary axis (16) parallel to a surface normal vector of the scintillation device (12), and wherein the scintillation device (12) comprises a wafer substrate (18) having a plurality of grooves (20), which are spaced apart from each other. Each of the grooves (20) extends to a depth (22) along a first direction (21) from a first side (13) of the scintillation device (12) into the wafer substrate (18), wherein each of the grooves (20) is at least partially filled with a scintillation material. Therein, the first direction (21) of at least a part of the plurality of grooves (20) is different from the primary axis (16), such that at least a part of the plurality grooves (20) is tilted with respect to the primary axis (16). An angle between the first direction (21) of a groove (20) arranged in a center region (24) of the scintillation device (12) and the primary axis (16) is smaller than an angle between the first direction (21) of a groove (20) arranged in an outer region (26) of the scintillation device (12) and the primary axis (16).