X-ray scintillation properties of an InGaN/GaN superlattice thin film

Abstract An 11-μm-thick InGaN/GaN superlattice was investigated as a fast X-ray scintillator. The superlattice exhibited a dominant emission peak at 412 nm. Biexponential fitting of the scintillation decay curve yielded a dominant decay component of 5.39 ns, while the second component accounted for only 0.34% of the total initial amplitude. Pulse-height measurements under 5.9- ( 55 Fe) and 59.5-keV ( 241 Am) irradiation showed clear photoabsorption peak. After correcting for the wavelength-dependent sensitivity of the photodetector and nonproportionality of GAGG:Ce, the light yield at 59.5 keV was estimated to be approximately 27,000 photons MeV -1 .