performance of the detector 1 the invention therefore proposes several manufacturing methods of an x ray detector 1 having a conversion layer 6 of red tetragonal pbo without a seeding layer 8 of yellow orthorhombic pbo according to a first group of embodiments of the inventive method the creation of the seeding layer 8 is prevented from the beginning this goal is achieved by providing additives during the initial growth of the pbo layer the additives influence the crystallisation process by increasing the mobility of the pb 2 and the o 2 u2212 ions of the just deposited layer by permitting the breaking and recreation of chemical bonds in this context h ions by addition of h 2 o and f u2212 ions by addition of hf nh 4 f or pbf 2 are particularly important in a series of experiments it has been shown that the additives are effective to improve the crystal quality of the pbo layer to reduce the number of defects and unsaturated surface states in the pbo layer and to prevent the formation of orthorhombic pbo in the seeding layer 8 one important additive is h2o which is added as a gas the addition in the gas phase is also preferred for all other additives having a melting or evaporation temperature which is more than 100 u00b0 c above or below the corresponding temperatures of pbo another important additive is pbf 2 which is co evaporated with pbo in this case two separate crucibles are provided that can be heated individually in the first crucible there is a.