An X-ray detector assembly includes a polymeric substrate having a lower surface and an upper surface, and an X-ray detector disposed on the upper surface of the substrate. The X-ray detector includes a thin-film-transistor array disposed on the substrate, an organic photodiode disposed on the thin-film-transistor array, and a scintillator disposed on the organic photodiode. A metal barrier extends substantially over an upper surface of the scintillator, substantially over peripherally-extending edges of the scintillator, the organic photodiode, and the thin-film-transistor array, and substantially over the lower surface of the substrate.