RADIATION DETECTOR CAPABLE OF MEASURING DEPTH-OF-INTERACTION

A radiation detector comprises a first scintillator having a first peak wavelength and a second scintillator positioned on the first scintillator. The second scintillator has a second peak wavelength different from the first peak wavelength. A plurality of photon detectors are provided. The first scintillator is positioned over and contacts each of the plurality of photon detectors. The plurality of photon detectors include first detectors and second detectors. The second detectors differ from the first detectors in doping profile, pn junction depth, or front-versus-backside illumination geometry. The first detectors are more sensitive to the first peak wavelength than the second peak wavelength. The second detectors are more sensitive to the second peak wavelength than the first detectors.