Low cost large area photodetector arrays are provided. In a first embodiment, the photodetectors comprise an inorganic photoelectric conversion material formed in a single thick layer of material. In a second embodiment, the photodetectors comprise a lamination of several thin layers of an inorganic photoelectric conversion material, the combined thickness of which is large enough to absorb incoming x-rays with a high detector quantum efficiency. In a third embodiment, the photodetectors comprise a lamination of several layers of inorganic or organic photoelectric conversion material, wherein each layer has a composite scintillator coating.